CalcaTools
calculate Calculators

Math Calculators

Algebra, geometry, statistics, probability, conversions and more — solve math problems instantly with our free calculators.

functions

0-60 Calculator | Estimate 0-60 mph acceleration time

Estimate a car's 0–60 mph time from weight, horsepower and drivetrain, using the standard empirical power-to-weight formula with an all-wheel, rear- and front-drive adjustment. Compare cars and modifications side by side before you buy.

Open Calculator arrow_forward
functions

34-Hour Reset Calculator | Find Reset Completion Time

Find exactly when your 34-hour off-duty reset completes from the start time, with the date rollover handled automatically. The essential schedule tool for truck drivers and fleet managers planning the 70-hour work week.

Open Calculator arrow_forward
functions

45-Minute Lunch Break Calculator | Paid hours after 45min lunch

Work out your paid hours by automatically deducting a 45-minute lunch break from any shift. Enter the clock-in and clock-out times and get the payable hours in both decimal and h:mm format — ready for timesheets and payroll checks.

Open Calculator arrow_forward
functions

60/40 Split Calculator | Divide a Total Into 60% and 40% Shares

Divide any total instantly into exact 60% and 40% shares, with the full-precision amounts shown. The fast way to split costs, profits, investments or bills by the classic 60/40 rule.

Open Calculator arrow_forward
functions

7-Minute Rule Calculator | Round Times To Nearest 15 Minutes

Round clock-in and clock-out times to the nearest quarter hour using the standard 7-minute rule — 1–7 minutes round down, 8–14 round up. Get the payable time for payroll and aviation duty logs, with the rounding shown.

Open Calculator arrow_forward
functions

Absolute Deviation Calculator | Compute absolute deviation

Measure how spread out your data really is with the mean absolute deviation, which averages the absolute differences from the mean. The tool shows every deviation step and also reports the median-based variant — a clear, outlier-friendly alternative to variance.

Open Calculator arrow_forward
functions

Angle Of Impact Calculator | Find impact angle from width, length

Calculate the angle of impact of a bloodstain from its width and length using the arcsin relationship, with the working shown. A standard tool for forensic pattern analysis and droplet studies — enter the two measurements and get the angle.

Open Calculator arrow_forward
functions

Antilog Calculator | Get antilog for base 10, e or custom

Find the antilog of any logarithm — base 10, natural or custom — returning the original number with the exponent form shown. Useful for reversing log-scale work in pH, decibels, chemistry and exponential growth problems.

Open Calculator arrow_forward
functions

Apparent Size Calculator | Angular size from object & distance

Find how large an object appears from a distance as an angular size, using the small-angle formula with the working shown. Essential for astronomy, photography framing and any size-versus-distance comparison.

Open Calculator arrow_forward
functions

APR to APY Converter | Convert APR to APY by compounding

Convert between APR and APY (EAR) for any compounding frequency, including continuous compounding, with the formula shown. The true cost of a loan and the true return on a deposit — enter either rate and get the other.

Open Calculator arrow_forward
functions

Aquarium Capacity Calculator | US gallons from tank dimensions

Find out exactly how many gallons and litres your aquarium holds from its inside dimensions, with the water volume after substrate and decor accounted for. The number you need for stocking levels, heater sizing and medication dosing.

Open Calculator arrow_forward
crop_square

Area Calculator | Compute shape areas with formulas

Pick a shape — rectangle, square, triangle, circle, trapezoid, parallelogram, or ellipse — enter the measurements, and this area calculator returns the result in square meters, square feet, acres, or other units. Every answer shows the formula and the numbers substituted, making it easy to follow for homework, flooring, tiling, and landscaping jobs.

Open Calculator arrow_forward
functions

Arithmetic Sequence Calculator | Compute Nth Term and Sum

Find the nth term and the sum of the first n terms of any arithmetic sequence, with the formula and working shown. Enter the first term and common difference and get any term in the sequence instantly.

Open Calculator arrow_forward
functions

Average Rate of Change Calculator | Find average rate of change

Find the average rate of change between two points on a function — the slope of the secant line — with the (y₂−y₁)÷(x₂−x₁) formula applied and each step shown. Essential for calculus preview, physics motion problems and understanding how fast quantities change over an interval.

Open Calculator arrow_forward
pin

Big Number Calculator | Compute arithmetic on big integers

Add, subtract, multiply, divide and raise exact integers with hundreds of digits — no scientific-notation rounding, no lost precision. Perfect for factorials, large products, cryptography practice and programming puzzles, with the full digit-by-digit working shown for every operation.

Open Calculator arrow_forward
memory

Binary Calculator | Convert Bases And Perform Binary Arithmetic

Convert instantly between binary and decimal, and perform binary arithmetic and bitwise logic like AND, OR and XOR. Each result includes the place-value breakdown, showing why binary place values are powers of two — ideal for computer science students and low-level debugging.

Open Calculator arrow_forward
functions

Binomial Formula Calculator | Binomial P(X=k) from n and p

Calculate binomial probabilities, cumulative probabilities, mean and variance for any number of trials, with log-space arithmetic that handles large n without overflow. Ideal for statistics coursework, quality sampling and probability modeling.

Open Calculator arrow_forward
functions

Boyle’s Law Calculator | Relate pressure and volume (Boyle’s Law)

Solve Boyle's law P₁V₁ = P₂V₂ for any pressure or volume change at constant temperature, with the inverse relationship explained. Enter three of the four values and get the fourth — the standard tool for gas compression and expansion problems in physics and chemistry.

Open Calculator arrow_forward
functions

Chi-Square Calculator | Compute χ² From Observed And Expected

Compute the chi-square statistic from observed and expected counts, with the degrees of freedom and p-value included. Run goodness-of-fit and independence tests with every term of the formula displayed.

Open Calculator arrow_forward
circle

Circle Calculator | Derive All Circle Measures From One Value

Enter the radius, diameter, circumference or area of a circle and the tool derives all the rest — radius, diameter, circumference, area — with the formulas shown. Use it for round tables, wheels, ponds and any geometry problem built on pi.

Open Calculator arrow_forward
monitoring

Coefficient Of Determination Calculator | Report R² & Regression

Measure how well a line explains your data with R-squared, the Pearson correlation and the regression equation, computed from paired x-y values. See the relationship strength and the fitted line's formula — the standard regression summary for coursework and data analysis.

Open Calculator arrow_forward
functions

Coefficient of Variation Calculator | CV from SD & mean

Measure relative variability with the coefficient of variation — standard deviation divided by the mean — in sample or population mode. Compare the consistency of data sets with very different scales, from finance risk to quality control.

Open Calculator arrow_forward
functions

Combined Gas Calculator | Final pressure from P, V & T

Solve combined gas law problems — final pressure, volume or temperature — from the other five values, with temperatures converted to kelvin automatically. The P₁V₁/T₁ = P₂V₂/T₂ relationship is applied with every step shown.

Open Calculator arrow_forward
percent

Confidence Interval Calculator | Get mean & proportion CIs

Builds a confidence interval for a mean or a proportion from your data. Enter the sample mean, sample size, standard deviation, and the confidence level — 90%, 95%, or 99% — and the tool computes the margin of error and the lower and upper bounds of the interval using the correct z-score or t-score.

Open Calculator arrow_forward
functions

Cross Product Calculator | Compute Vector Cross Product

Calculate the cross product of two 3D vectors — the perpendicular vector, its magnitude and the parallelogram area it spans — with the component-by-component working displayed. Ideal for physics, computer graphics and geometry problems.

Open Calculator arrow_forward
functions

Diamond Problem Calculator | Find Numbers With Sum & Product

Solve diamond problems — find two numbers that add to the top value and multiply to the bottom — with the quadratic formula shown. The classic algebra factoring tool for students and teachers.

Open Calculator arrow_forward
functions

Dimensional Analysis Calculator | Convert units, check dimensions

Convert between any compatible units by chaining conversion factors, with every cancellation step shown. Enter the value and the unit path, and the tool multiplies through the ratios so the units cancel cleanly — the reliable way to avoid unit errors in science and engineering.

Open Calculator arrow_forward
social_distance

Distance Calculator | Compute coordinate distance in mi, km, or NM

Find the straight-line distance between two points in 2D or 3D space using the distance formula. Enter coordinates and the tool shows the squared differences and the square-root step, making it easy to verify geometry homework, map calculations and engineering layouts.

Open Calculator arrow_forward
functions

Drop Chance Calculator | Estimate An Item’s Drop Probability

Calculate the chance of getting a drop in games — the probability over multiple attempts, the expected number of runs, and how many runs you need for a 90% or 99% confidence. The cumulative probability math is shown, so you know whether to keep grinding or accept the odds.

Open Calculator arrow_forward
functions

Dry Well Calculator | Estimate volume from area & rainfall

Size a dry well for stormwater from your drainage area and rainfall, returning the required volume in cubic feet and gallons with the gravel void space accounted for. The practical tool for rain gardens and drainage projects.

Open Calculator arrow_forward
timeline

Endpoint Calculator | Compute Missing Endpoint From Midpoint

Find the missing endpoint of a line segment from its midpoint and one endpoint, with the doubling formula shown, plus the length and slope. The essential tool for geometry and coordinate problems.

Open Calculator arrow_forward
functions

Energy Foot-Pounds Calculator | Work from force & distance

Calculate mechanical work in foot-pounds from force and distance, then convert to joules and kilojoules with the exact factor. The formula Work = Force × Distance is applied with each step shown — essential for physics homework, torque work and engineering estimates.

Open Calculator arrow_forward
functions

Error Function Calculator | Evaluate erf(x) For A Given X

Compute the error function erf(x) and its complement erfc(x) to high precision for any real input. Both values are returned together — essential for statistics, diffusion and heat-transfer problems and normal-distribution calculations.

Open Calculator arrow_forward
functions

Exponent Calculator | Compute Powers For Any Real Exponent

Raise any number to a power — integer, negative, fractional or decimal — and see the result with full precision. Handles scientific notation and large exponents, with the working shown for each step. Useful for growth problems, compound calculations and algebra practice.

Open Calculator arrow_forward
numbers

Factor Calculator | List All Factors And Prime Factorization

List every factor of any whole number, with the factor pairs and the complete prime factorization shown. Perfect for simplifying fractions, finding common denominators, solving algebra puzzles and checking divisibility — the prime factors are displayed step by step.

Open Calculator arrow_forward
functions

Fill Dirt Calculator | Estimate fill dirt volume for a job

Estimate how much fill dirt you need in cubic yards and tons for any excavation or grading project. Enter the length, width and depth, and the tool converts the volume to weight using standard soil density — essential for ordering and budgeting earthwork.

Open Calculator arrow_forward
functions

Flow Capacity Calculator | Flow from diameter & velocity

Calculate how much liquid a pipe or channel can carry from its diameter and flow velocity, using Q = A × v with the cross-sectional area shown. Results in cubic feet per second and gallons per minute — essential for plumbing, irrigation and drainage design.

Open Calculator arrow_forward
functions

Foundation Squaring Calculator | Check Squareness Via Diagonal

Find the exact diagonal measurement that makes your foundation corners perfectly square, using the extended 3-4-5 rule on any rectangle. Enter the two side lengths and the tool returns the diagonal both must match — the standard check for construction layout.

Open Calculator arrow_forward
percent

Fraction Calculator | Compute And Simplify Fraction Operations

Add, subtract, multiply and divide fractions with exact results — never rounded. The tool finds common denominators, simplifies every answer to lowest terms and shows the full working, converting between improper fractions and mixed numbers along the way.

Open Calculator arrow_forward
functions

Fraction To Decimal Calculator | Handle repeating decimals

Convert any fraction or mixed number to a decimal with long division shown, marking terminating and repeating decimals. Also converts decimals back to fractions — the complete two-way converter for exact math work.

Open Calculator arrow_forward
functions

Fraction To Percent Calculator | Convert Fractions To Percentages

Convert fractions to percentages and back instantly, with the division step shown for every conversion. Handle proper, improper and mixed fractions — including repeating decimals like one third — with exact results.

Open Calculator arrow_forward
functions

G-Force Calculator | Calculate g From Acceleration

Convert acceleration into g-force, the standard multiple of Earth's gravity, with the formula shown for both linear and circular motion. Essential for amusement park physics, motorsport, aerospace and engineering — enter the acceleration and get the g's.

Open Calculator arrow_forward
functions

GCF Calculator | Find Greatest Common Factor And LCM With Steps

Enter up to five numbers and this GCF calculator returns their greatest common factor using the Euclidean algorithm, with the step-by-step divisions shown. It also lists the factors of each number and reports the least common multiple, giving you both classic results for fraction reduction and ratio problems in one go.

Open Calculator arrow_forward
functions

Geographic Midpoint Calculator | Find great-circle midpoint

Find the true geographic midpoint between two locations using great-circle spherical geometry — not simple coordinate averaging. Also returns the distance between them, making it ideal for planning meetups, comparing routes and understanding geography.

Open Calculator arrow_forward
functions

Geometric Mean Rate Of Return Calculator | Geometric return

Calculate the true average annual return of an investment portfolio using the geometric mean, which accounts for compounding. Unlike the arithmetic average, it reflects actual growth — essential for comparing fund and portfolio performance.

Open Calculator arrow_forward
science

Half-Life Calculator | Solve half-life time or quantity

Models radioactive decay and exponential decay problems. Enter any three of the initial quantity, remaining quantity, elapsed time, and half-life, and the tool solves for the missing value using N = N0 × (1/2)^(t/T), with the working shown. Used for radiometric dating, medication dosing, and decay homework.

Open Calculator arrow_forward
tag

Hex Calculator | Convert Bases And Perform Hexadecimal Arithmetic

Add, subtract, multiply and divide hexadecimal numbers, and convert between hex, decimal and binary instantly. Ideal for programmers working with memory addresses, color codes, bit manipulation and embedded systems, with the digit-by-digit working displayed.

Open Calculator arrow_forward
functions

Ideal Gas Calculator | Compute Gas Variables Using PV = nRT

Solve the ideal gas law PV = nRT for pressure, volume, moles or temperature, with unit conversions and the gas constant applied. Enter any three values and get the fourth — the essential tool for chemistry and physics gas problems, with temperature handled in kelvin automatically.

Open Calculator arrow_forward
functions

Inverse Cos Calculator | Compute arccos for inputs -1 to 1

Convert a cosine ratio to its angle with arccos, in degrees or radians, including the supplementary solution. Shows the principal range and the unit-circle reasoning — ideal for right-triangle trigonometry and physics problems.

Open Calculator arrow_forward
functions

Inverse Sin Calculator | Find Arcsine in Degrees or Radians

Convert a sine ratio to its angle with arcsin, in degrees or radians, including the second solution in the full circle. Shows the principal range — ideal for trigonometry, physics and engineering problems.

Open Calculator arrow_forward
functions

KE Calculator | Calculate kinetic energy from mass and velocity

Calculate kinetic energy from mass and speed with the formula KE = ½mv², showing why speed matters more than mass. Results are given in joules and foot-pounds with real-world context — ideal for physics homework, vehicle safety and engineering estimates.

Open Calculator arrow_forward
functions

Lbs to Liters Converter | Convert Pounds to Liters Using Density

Convert pounds to liters for water, oil, milk, gasoline, honey and custom liquids using each liquid's density. Because a liter is a volume and a pound is a weight, the density is the bridge — the tool applies it with the working shown.

Open Calculator arrow_forward
functions

LCD of Fractions Calculator | Find Least Common Denominator

Find the least common denominator of two or more fractions using the LCM of their denominators, with the factor working shown. Convert each fraction to its equivalent with the common denominator — the essential first step for adding and comparing fractions with different bottoms.

Open Calculator arrow_forward
numbers

LCM Calculator | Find LCM and GCF using prime factors

Find the least common multiple of up to five numbers using prime factorization, with the factor breakdown for every input shown. Essential for adding and comparing fractions, scheduling repeating events and solving ratio problems — the working is fully transparent.

Open Calculator arrow_forward
functions

Leap Year Calculator | Determine If a Year Is a Leap Year

Check whether any year is a leap year with the full Gregorian rule explained — divisible by 4, except centuries unless divisible by 400. Perfect for date math, calendar work and satisfying that 'was it a leap year?' question.

Open Calculator arrow_forward
functions

Limiting Reactant Calculator | Find limiting reactant by amounts

Identify which reactant runs out first in any chemical reaction, how much excess remains, and the theoretical yield it produces. Enter the masses and balanced-equation coefficients and the tool walks through the mole comparisons — a must-have for stoichiometry.

Open Calculator arrow_forward
functions

Log Base 2 Calculator | Compute Base-2 Logarithms Instantly

Compute the base-2 logarithm of any number with the change-of-base formula shown, plus the exact result for powers of two. Essential for information theory, algorithm analysis, binary math and computer science coursework.

Open Calculator arrow_forward
functions

Log Calculator | Evaluate Logarithms In Any Base And Reverse Logs

This log calculator evaluates logarithms in any base you choose — base 10, natural log (ln), or a custom base. Enter a number and the tool returns the logarithm with its full working, and it can also reverse the calculation: given a log value, it finds the original number. Ideal for chemistry pH work, decibel math, and algebra homework.

Open Calculator arrow_forward
grid_view

Matrix Calculator | Compute operations, determinant, and inverse

Add, subtract, multiply, transpose and invert matrices up to any practical size, with every step of the working shown. Compute determinants and solve systems of linear equations — the tool walks through each row-column multiplication so you can verify the result.

Open Calculator arrow_forward
analytics

Mean Median Mode Calculator | Get mean, median, mode & count

Enter a list of numbers and get the mean, median, mode, range, sum and count in one step, with the sorted data shown. The complete descriptive summary makes it easy to compare data sets, check homework and spot outliers before they mislead you.

Open Calculator arrow_forward
functions

Mean Squared Error Calculator | MSE between obs & preds

Evaluate how accurate a model's predictions are with mean squared error, root mean squared error and mean absolute error, with the working for each term. Essential for regression analysis, forecasting and machine learning evaluation.

Open Calculator arrow_forward
functions

Midpoint Formula Calculator | Find Midpoint Between Two Points

Find the midpoint of a line segment from its two endpoints using the average formula — add the coordinates and divide by two — with the working shown for 2D and 3D points. The essential geometry tool for bisectors, circle centers and coordinate problems.

Open Calculator arrow_forward
percent

Modulo Calculator | Compute Remainder and Show Division Working

Computes the remainder of a division, also known as a mod operation. Enter a dividend and a divisor, and the tool returns a mod n using standard mathematical convention, handling positive and negative numbers correctly. The quotient and the full division working are shown, making it ideal for programming and number-theory homework.

Open Calculator arrow_forward
functions

Months To Weeks Converter | Convert Months Into Weeks

Convert months to weeks and weeks to months using the average month length, with exact calendar equivalents available. Perfect for pregnancy timelines, project planning, contracts and any duration math where months and weeks need reconciling.

Open Calculator arrow_forward
functions

Multiples Calculator | Find The N-th Multiple Of A Number

Generate the first n multiples of any number instantly, with the multiplication shown for each. Perfect for finding common multiples, fraction work, scheduling repeating events and pattern practice.

Open Calculator arrow_forward
functions

Multiply Recipe Calculator | Scale ingredients for servings

Scale any recipe to the servings you need — double, triple, or any factor — with every ingredient converted automatically. Perfect for cooking for a crowd, adjusting baking recipes and meal planning.

Open Calculator arrow_forward
functions

Nautical Mile Converter | Convert Nautical Miles to Kilometers

Convert between nautical miles, statute miles, kilometers and feet, plus knots to mph and km/h, with the latitude-based definition explained. Essential for aviation, maritime navigation and international distance comparisons.

Open Calculator arrow_forward
functions

Net Terms Calculator | Find Invoice Due Date From Net Days

Find the exact due date of an invoice for Net 15, 30, 45, 60 or 90 payment terms, from the invoice date. Track receivables and avoid late fees — enter the invoice date and term and get the deadline instantly.

Open Calculator arrow_forward
functions

Newton Calculator | Calculate Force From Mass and Acceleration

Convert mass to force in newtons with F = m × g, and understand the difference between mass and weight. Enter the mass in kilograms and the tool returns the gravitational force in newtons — the standard conversion for physics and engineering.

Open Calculator arrow_forward
functions

Normal Distribution Calculator | Get Probabilities and Z-Scores

Find probabilities, percentiles and z-scores for any normal distribution — enter the mean, standard deviation and value or range, and get the cumulative probability with the empirical rule context. Essential for statistics and quality analysis.

Open Calculator arrow_forward
functions

NPV Calculator | Calculate NPV From Cash Flows and Discount Rate

Calculate net present value and profitability index from a series of future cash flows and a discount rate, with each discounted term shown. The essential tool for evaluating investments, projects and business decisions.

Open Calculator arrow_forward
functions

P-Value Calculator for Student t-Test | P-value from t and df

Compute the p-value for a Student's t-test from your t-statistic and degrees of freedom, with the one- and two-tailed options. The significance conclusion is explained — essential for hypothesis testing in statistics coursework and research.

Open Calculator arrow_forward
functions

P-Value From Z Calculator | Convert Z-Score To P-Value

Convert a z-score into a p-value for one- and two-tailed hypothesis tests, with the standard normal curve explained. The quick significance check for statistics coursework and research.

Open Calculator arrow_forward
functions

Pallet Cube Calculator | Cubic feet from pallet dimensions

Calculate the cubic footage and cubic meters of a loaded pallet from its dimensions — the volume figure freight carriers quote from. Essential for LTL shipping quotes, warehouse planning and freight class estimates.

Open Calculator arrow_forward
functions

Percent Deviation Calculator | Percent deviation from reference

Measure how far a result deviates from an accepted value as a percentage, using the standard percent-deviation formula with the absolute difference shown. Ideal for lab experiments, quality checks and calibration verification.

Open Calculator arrow_forward
functions

Percent Error Calculator | Compute Absolute And Relative Error

Calculate percent error between a measured and accepted value with the absolute-value formula shown, plus the absolute difference. The standard lab-quality metric for calibration and experiment accuracy.

Open Calculator arrow_forward
percent

Percentage Calculator | Solve X% Of Y And Percent Change

Solve every percentage problem in one place: find X% of Y, work out what percent X is of Y, calculate percent change, or find the whole when only a part is known. Each result shows the formula and working, for shopping discounts, tips, grades and financial math.

Open Calculator arrow_forward
percent

Percentile Range Calculator | Get Spread Between Two Percentiles

Compute the spread between any two percentiles — the interquartile range, P10–P90, or any custom band — with the interpolation shown. Understand the middle of your data and identify outliers with the 1.5×IQR rule.

Open Calculator arrow_forward
pin

Permutation Combination Calculator | Calculate nPr And nCr

Calculate permutations (nPr) and combinations (nCr) with the full factorial working shown. Perfect for probability problems, lottery odds, scheduling arrangements and counting questions — enter n and r and get both values, plus the reasoning behind each.

Open Calculator arrow_forward
functions

Polygon Perimeter Calculator | Find Perimeter From Side Length

Find the perimeter of any polygon — regular or irregular — from its side lengths, with interior angles for regular shapes. Enter the sides and get the total boundary length, ideal for fencing, framing and geometry.

Open Calculator arrow_forward
functions

Pool Volume Calculator | Compute Pool Gallons From Dimensions

Determine your pool's volume in gallons and litres from the length, width and average depth, with the shape-specific formula applied. The gallon figure sizes your pump, filter and chemical doses — enter the pool's dimensions and get the numbers you need.

Open Calculator arrow_forward
groups

Population Proportion Calculator | Estimate Proportion: SE & CI

Estimate a population proportion from sample counts, with the sample proportion, standard error and confidence interval shown. The essential survey-statistics tool for polls and research, with the normal-approximation condition checked.

Open Calculator arrow_forward
functions

Population Rate Calculator | Compute Rate Per 1,000 Or 100,000

Calculate crude rates, incidence and prevalence per 1,000 or 100,000 population, with the correct population-at-risk guidance. The standard public-health and demographic rate calculations, explained and applied.

Open Calculator arrow_forward
percent

Probability Calculator | Calculate probabilities and odds for events

Work out the probability of single and combined events — both happening, either happening, or at least one happening — with the multiplication and addition rules applied and explained. Ideal for dice, cards, raffles and any chance-based decision.

Open Calculator arrow_forward
square_foot

Pythagorean Calculator | Solve Right Triangles For Missing Side

Solve any right triangle with the Pythagorean theorem: find the hypotenuse from two legs, or find a missing leg from the hypotenuse and one leg. The squared steps are shown, and the tool also confirms whether three side lengths form a right triangle — a staple for construction and geometry.

Open Calculator arrow_forward
functions

Quadratic Formula Calculator | Find roots and discriminant

Solve any quadratic equation ax² + bx + c = 0 with the quadratic formula, showing the discriminant step and both roots. Real and complex roots are both handled, with the working fully displayed — ideal for algebra homework, physics problems and graphing checks.

Open Calculator arrow_forward
percent

Ratio Calculator | Simplify ratios, convert, and solve proportions

Simplify ratios to lowest terms and convert them to fractions, percentages and decimals in one step. Enter two or three numbers and the tool divides by the greatest common factor and shows the working — essential for recipes, mixing, and comparing proportions.

Open Calculator arrow_forward
square_foot

Right Trapezoid Calculator | Solve Geometry From Bases and Height

Calculate the area, slant side, perimeter, diagonals and angles of a right trapezoid from its bases and height, with the Pythagorean step for the slant side shown. The complete solution for trapezoid problems.

Open Calculator arrow_forward
functions

Right Triangle Calculator | Solve sides, angles & area

Solve any right triangle from two sides or a side and an angle — the Pythagorean theorem finds the missing side, trigonometry the angles, and the area and perimeter follow. The complete solution with every step displayed.

Open Calculator arrow_forward
functions

RNG Simulator | Generate Random Integers Between Min and Max

Simulate cryptographically secure random draws in any range, from dice and coins to custom probability setups, with large batch support and live distribution display. Understand streaks and fairness with a source you can trust.

Open Calculator arrow_forward
functions

Root Calculator | Compute Square, Cube, Or Any Nth Root Precisely

Find the square root, cube root or any nth root of a number to high precision, with the exponent form shown. Handles perfect roots exactly and irrational roots to many decimal places — ideal for geometry, physics and algebra work.

Open Calculator arrow_forward
pin

Rounding Calculator | Round to decimals or significant figures

Round any number to a chosen decimal place, whole number, ten, hundred, thousand or a set number of significant figures, with the rounding decision explained. Includes the half-up rule and shows both the rounded value and the precision retained.

Open Calculator arrow_forward
analytics

Sample Size Calculator | Find required sample size for confidence & margin

Determine how large a survey sample you need for a chosen confidence level, margin of error and population size. Uses the standard sample-size formula with the 50% worst-case assumption explained — essential for planning polls, experiments and market research.

Open Calculator arrow_forward
functions

Scientific Calculator | Evaluate trig, logs, exponentials, and powers

A full-featured online scientific calculator with trigonometric functions (sin, cos, tan in degrees or radians), logarithms, exponentials, powers, roots, factorials, and constants like pi. It evaluates complex expressions with proper operator precedence, keeps a calculation history, and works on any device — no install or sign-up.

Open Calculator arrow_forward
functions

Scientific Notation Calculator | To/from scientific notation

Convert any number to and from scientific notation instantly, with the decimal-point movement shown. Handle huge and tiny values — Avogadro's number, Planck's constant, distances in light-years — with full precision.

Open Calculator arrow_forward
functions

Sector Calculator | Compute Area From Radius and Radian Angle

Calculate the area, arc length, chord length and perimeter of any circle sector from the radius and angle, in degrees or radians. Essential for pie portions, gear segments, irrigation coverage and circular statistics.

Open Calculator arrow_forward
functions

Sigma Level Calculator | Sigma from defects & opportunities

Convert defects per million opportunities (DPMO) into a sigma level and yield percentage, with and without the 1.5-sigma shift. The standard Six Sigma quality metric — enter your defect count and get the process capability.

Open Calculator arrow_forward
functions

Sin-Cos Converter | Convert between sine & cosine

Convert between sine and cosine, and degrees and radians, using the unit-circle identities with the working shown. Includes the exact values for common angles — ideal for trigonometry homework and physics.

Open Calculator arrow_forward
functions

Sine Bar Calculator | Compute Height From Bar Length And Angle

Calculate the gauge-block stack height needed to set a precise angle with a sine bar, using H = L × sin(θ). Enter the sine-bar length and target angle and get the exact stack — a fundamental setup calculation for machining and inspection.

Open Calculator arrow_forward
bar_chart

Skewed Distribution Calculator | Skewness, kurtosis & shape

Measure how skewed your data is with sample skewness, excess kurtosis and the mean-versus-median comparison, with a plain-English shape classification. The fast way to understand distribution shape before choosing summary statistics.

Open Calculator arrow_forward
linear_scale

Slope Calculator | Compute slope and slope-intercept form from two points

Find the slope between two points as rise over run, then get the complete line equation in slope-intercept form with the intercept shown. Ideal for algebra homework, rate-of-change problems and graphing — the tool displays the full working for each step.

Open Calculator arrow_forward
functions

Square Cube Law Calculator | Demonstrate Area and Volume Scaling

See how scaling an object's length changes its surface area and volume — area grows as the square, volume as the cube. The classic explanation of why animals have size limits, used in biology, engineering and scaling problems.

Open Calculator arrow_forward
show_chart

Standard Deviation Calculator | Compute mean, variance & std dev

Calculate the standard deviation and variance of any data set, choosing sample or population mode, with the squared deviations shown. The complete spread analysis — mean, variance, standard deviation — makes it easy to understand how consistent your data really is.

Open Calculator arrow_forward
functions

Standards Grading Calculator | Weight scores with decay

Average standards-based assessment scores with the method your school uses — decaying average, simple average or banded letter conversion — with the working shown. Enter the scores and get the overall level and percentage under your chosen method, plus guidance on how each approach weights recent performance.

Open Calculator arrow_forward
bar_chart

Statistics Calculator | Compute Mean, Median, Mode & Quartiles

Get the full descriptive statistics of any data set in one click: count, sum, mean, median, mode, range, variance, standard deviation, quartiles and skewness, with the sorted data displayed. The complete summary is ideal for coursework, quality reports and data analysis.

Open Calculator arrow_forward
functions

Summation of Series Calculator | Sum arithmetic series from a,d,n

Sum arithmetic and geometric series with the nth-term formula and the sum formula shown step by step. Enter the first term, difference or ratio, and the number of terms — ideal for sequences homework and financial projections.

Open Calculator arrow_forward
functions

Surface Area Calculator | Find Total And Lateral Surface Area

Calculate the surface area of cubes, prisms, cylinders, spheres, cones and pyramids from their dimensions, with volume also returned. Perfect for painting, coating, heat-transfer and packaging estimates — the formulas are shown.

Open Calculator arrow_forward
functions

Tank Volume Calculator | Compute Tank Gallons From Dimensions

Calculate the capacity of rectangular and cylindrical tanks in gallons and litres from their interior dimensions, with partial-fill support. Perfect for aquariums, fuel storage, water tanks and chemical vessels — the volume math is shown step by step.

Open Calculator arrow_forward
functions

Terminal Value Calculator | Gordon growth terminal value

Estimate a company's terminal value with the Gordon growth model from its final cash flow, perpetual growth rate and discount rate, with the r > g condition enforced. The majority of any DCF valuation — essential for finance coursework and analysis.

Open Calculator arrow_forward
functions

Theoretical Yield Calculator | Compute theoretical yield

Find the maximum product a chemical reaction can produce by identifying the limiting reactant and converting through mole ratios and molar mass. The complete stoichiometry is shown step by step — essential for chemistry labs, percent-yield calculations and experiment planning.

Open Calculator arrow_forward
functions

Tonnage Calculator | Calculate Tonnage From Given Dimensions

Work out how many tons of gravel, topsoil or aggregate you need from the length, width and depth of an area, with the cubic-yard volume shown first. Uses standard material densities and includes the coverage per yard — essential for ordering and budgeting.

Open Calculator arrow_forward
change_history

Triangle Calculator | Solve Sides, Angles, Area & Perimeter

Solve any triangle from three sides, two sides and an angle, or two angles and a side — the tool returns all missing sides, angles, area and perimeter. Right triangles use the Pythagorean theorem and oblique triangles use the sine and cosine laws, with full working shown.

Open Calculator arrow_forward
functions

Tube Calculator | Calculate Tube Volume From OD, ID, and Length

Calculate the volume, surface area and wall thickness of a cylindrical tube from its outside and inside dimensions, with gallon and litre conversions. Perfect for pipes, hollow shafts and tubing in engineering and construction.

Open Calculator arrow_forward
functions

Upper and Lower Bound Calculator | Bounds from value & unit

Find the upper and lower bounds of a rounded measurement — the half-open interval the true value must lie in. Enter the value and its precision and the tool returns both bounds with the rounding convention explained, essential for error analysis.

Open Calculator arrow_forward
functions

Variance Calculator | Calculate variance from data samples

Calculate the variance of your data set in sample or population mode, with each squared deviation shown and the mean displayed. The complete step-by-step working makes it easy to follow how the spread of your data is computed — the foundation of statistics.

Open Calculator arrow_forward
functions

Vector Subtraction Calculator | Difference from components

Subtract 2D or 3D vectors component by component, then get the resulting magnitude and direction angle with the working shown. Essential for physics displacement problems, engineering and graphics work.

Open Calculator arrow_forward
view_in_ar

Volume Calculator | Compute Volume of Common 3D Shapes

Calculate the volume of boxes, cylinders, spheres, cones, pyramids and prisms, with conversions to gallons and litres included. Enter the dimensions and the tool applies the correct formula — perfect for tanks, aquariums, concrete and shipping estimates.

Open Calculator arrow_forward
functions

Weeks From Today Calculator | Find Date After a Number of Weeks

Find the exact date a given number of weeks from today — or from any start date — with the weekday shown. Calendar arithmetic handles month lengths and leap years, making it perfect for deadlines, countdowns and planning.

Open Calculator arrow_forward
functions

Year-Over-Year Change Calculator | Compute YoY Percent Change

Calculate the year-over-year percentage change between two values, with the formula and the direction of growth shown. Ideal for revenue, prices, metrics and any comparison against the same period last year — negative bases are handled correctly.

Open Calculator arrow_forward
analytics

Z-Score Calculator | Compute Standard Score and Percentile

Convert any raw score to a z-score and percentile using the population mean and standard deviation, with the formula shown. Essential for comparing values across different scales, interpreting test results and understanding the normal distribution.

Open Calculator arrow_forward
functions

Z-Test Calculator | Compute Z Statistic For A Sample Mean

Run a one-sample z-test: enter the sample mean, hypothesized mean, population standard deviation and sample size, and get the z-statistic, degrees of freedom and p-value. The significance conclusion is explained — essential for statistics coursework and research.

Open Calculator arrow_forward