GCD & LCM Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
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Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter two whole numbers.
- Press Calculate for the GCD and LCM.
How it works
The GCD (greatest common divisor) is the largest number that divides both. The LCM (lowest common multiple) is the smallest number both divide into: LCM = a × b ÷ GCD.
Worked example
12 and 18. GCD = 6, LCM = 12 × 18 ÷ 6 = 36.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.