CalcaTools

Leap Calculator

Calculates leap year using Leap year if divisible by 4, except centuries not divisible by 400, live in your browser.

Last updated: June 2026 · Free · No sign-up required

Results

Enter values above and click Calculate to see your result instantly.

What the Leap Calculator does

Behind the inputs above sits one rule: Leap year if divisible by 4, except centuries not divisible by 400. The tool evaluates it instantly with the values you enter.

Scroll past the calculator for a quick-reference table, a step-by-step methodology with a fully worked example, and answers to the questions people most often ask about leap year calculator.

Quick reference

YearLeap?Reason
2024YesDivisible by 4
1900NoCentury, not ÷400
2000YesCentury ÷ 400
2026NoNot divisible by 4

functions Shows the working, not just the answer

For students and teachers, the final number is only half the value. Every math tool here exposes the formula it applied, the intermediate steps, and the rounding rule, so you can follow along, check your homework, or use the answer in a proof or report with confidence.

calculate Accurate to the spec

Calculations use 64-bit floating point with sensible rounding for the domain (currency to 2 decimals, percentages to 4 decimals, algebra to 6 significant figures). Where exact rational arithmetic matters — fractions, factorials, simplification — we use a dedicated BigNumber path so 1/3 + 1/6 returns ½, not 0.49999.

school Free for classroom use

Educators are welcome to link to any math calculator on CalcaTools from a class site, Google Classroom, or worksheet. The pages are mobile-friendly, free, ad-supported (so we can keep them free) and have no sign-up wall — students just click and use them in class or at home.

tips_and_updates Pair with the spoke articles

Below the calculator we link a small set of plain-English explainer pages — "What is a percentage?", "Why does PEMDAS matter?", and so on. They cover the underlying concept in 4–6 short paragraphs. Read those before the calculator if the topic is new, or after if you want the extra context.

Interpretation guide

ResultMeaning
Leap year366 days, February has 29
Common year365 days, February has 28
Next leap yearUpcoming year with Feb 29

Formula & methodology

Formula: Leap year if divisible by 4, except centuries not divisible by 400

  1. Enter the four-digit year you want to test.
  2. Check divisibility by 4; if not divisible, it is a common year.
  3. If it is a century year, it must also be divisible by 400 to be a leap year.
  4. The tool reports leap status, February days, total days and the next leap year.

Example: 2028 is a leap year (divisible by 4 and not a century), so February has 29 days and the year has 366.

Frequently asked questions

How do I know if a year is a leap year?
A year is a leap year if it is divisible by 4, unless it is a century year that is not divisible by 400 (so 1900 was not, 2000 was).
Is 2026 a leap year?
No. 2026 is not divisible by 4, so it is a common year of 365 days; the next leap year is 2028.
Why are some century years not leap years?
The 400-year rule corrects the small over-count of the simple 4-year rule, keeping the calendar aligned with the solar year.
How many days are in a leap year?
A leap year has 366 days, with 29 days in February instead of 28.
Is the leap year calculator free?
Yes, it is free, requires no sign-up, and runs in your browser.