GCD & LCM Calculator
Find the greatest common divisor and least common multiple of two or more whole numbers, with the Euclidean algorithm steps for the first pair.
Runs on your device
Result
Results appear here as you type.
What it does
Enter numbers separated by commas or spaces. The GCD uses the Euclidean algorithm, shown step by step so you can reproduce it in an exam.
How to use it
- Enter two or more whole numbers.
- Read the GCD and LCM.
- Review the Euclidean steps.
Example
gcd = 12, lcm = 252. Select Try an example above to see it.
When it helps
- Simplifying fractions.
- Scheduling repeating events.
- Number theory practice.
Questions
What is the GCD of a number and 0?
The number itself; gcd(n, 0) = |n|.
How is LCM computed?
lcm(a, b) = |a × b| ÷ gcd(a, b), applied pairwise across the list.
More student & maths tools
See all 12- Definite Integral Calculator (Numerical) Numerically evaluate a definite integral of f(x) between two limits using Simpson’s rule, with the formula, step size and a trapezoidal cross check.
- Permutation & Combination Calculator Calculate nPr and nCr (combinations) exactly for large n using BigInt, plus factorials, with the formulas and substituted values shown.
- Scientific Expression Calculator Evaluate expressions such as 2sin(30) + sqrt(16)/3 with trig, logs, powers and factorials, in degrees or radians, without using eval.
- Quadratic Equation Solver Solve ax² + bx + c = 0 with full working: the formula, substituted values, discriminant and real or complex roots, step by step.
- Percentage Calculator Work out X% of Y, what percent one number is of another, percentage increase or decrease, and add or subtract a percentage, with the working shown.
- GPA & CGPA Calculator (4.0 scale) Calculate semester GPA and updated CGPA from letter grades and credit hours on the 4.0 scale used by FAST NUCES and many other universities.
People also use
Browse all 200 tools- Fancy Text Generator Turn plain text into bold, italic, script, circled, monospace and upside down Unicode text you can paste into Instagram, X and TikTok bios. Quick utilities
- URL Encoder & Decoder Percent encode or decode URL components and full URLs. Handles Unicode and reports malformed escape sequences instead of failing silently. Developer
- Word Frequency Counter List the most frequent words in a text with counts and percentages, optionally ignoring common English stop words. Export the table as CSV. Text & writing
- Online Timer A free countdown timer with one click presets from 1 minute to 1 hour, a loud alarm, fullscreen view and keyboard shortcuts. No sign up or install. Time & productivity