GCD & LCM Calculator
Enter a list of whole numbers to get their GCD and LCM at once.
How to use it
- Enter two or more whole numbers Separate them with commas or spaces.
- Read the GCD and LCM Both update instantly.
Examples
| GCD of 24, 36, 60 | 12 |
|---|---|
| LCM of 4, 6, 8 | 24 |
| GCD of 17, 5 | 1 |
About this tool
The greatest common divisor and least common multiple turn up in simplifying fractions, scheduling repeating events and many number-theory problems.
This calculator computes both for any list of whole numbers using Euclid’s algorithm, which is fast and exact. Everything runs in your browser.
Frequently asked questions
What is the greatest common divisor?
The GCD is the largest whole number that divides all the given numbers exactly. For 12 and 18 it is 6.
What is the least common multiple?
The LCM is the smallest number that is a multiple of all the given numbers. For 4 and 6 it is 12.
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Updated June 12, 2026