Health Calculators
Health Calculators — guides, articles and tools from CalcaTools covering every topic in this category. Free, fast, browser-based explainers with no sign-up.
Water Intake Calculator Guide: How Much Water Do You Actually Need Every Day?
Water intake calculator guide that reviews common rules like eight 8-ounce glasses and examines the science behind how much water you actually need each day.
How Many Calories Should You Eat to Lose Weight?
How many calories to eat to lose weight: calculate TDEE, use a 500-calorie deficit for ~1 lb/week, with protein targets and safe floors.
Ideal Weight for Your Height: Formulas, Charts and How to…
Find ideal weight using Devine, Robinson, and Miller formulas or the BMI healthy range (18.5–24.9), with charts and body-composition notes.
Body Fat Percentage: How It’s Measured, Which Metho…
Body fat percentage methods compared: calipers, BIA, DEXA and the Navy formula; how each works, which to trust and the ranges considered healthy.
Pregnancy Due Date Calculation: Naegele’s Rule, LMP…
Pregnancy due date calculation: Naegele’s rule and LMP math, why the 40-week estimate is often a week off, and how the early dating scan corrects it.
TDEE Calculator Explained: How to Find Your Real Daily Ca…
Learn what TDEE is, why it's key for fat loss, recomp or muscle gain, how it's calculated, common calculator errors and how to apply it.
BMI Categories Explained: What Your Number Actually Means
Understand what your BMI number means, its limits for body composition, and what each BMI category actually indicates.
How BMI Is Calculated: The Simple Math Behind the Score
How BMI is calculated: the simple math behind the Body Mass Index score, how weight and height produce the number, and why the medical world relies on BMI.
Limitations of BMI: Why Your Scale is Lying to You
Explains BMI limitations and how it can mislabel muscular, low-body-fat people as obese, shown by a fit rugby player whose BMI triggered a red warning.