➗ GCD and LCM Calculator
Paste a list of integers and get the GCD, LCM and a short Euclidean trace for the first pair. Useful for fractions, schedules and ratios.
Input
Result
Summary
Private by design. This tool runs entirely in your browser — nothing you enter or add is uploaded to any server.
How it works
- Enter two or more integers separated by commas, spaces or new lines.
- Press Calculate. GCD uses the Euclidean algorithm; LCM uses GCD so products do not overflow early.
- Read the shared divisor, the common multiple and the step trace.
Examples
- 12 and 18 have GCD 6 and LCM 36.
- 8, 12 and 20 have GCD 4 and LCM 120.
- Coprime inputs such as 7 and 13 have GCD 1.
Frequently asked questions
Can I use more than two numbers?
Yes. The calculator folds GCD and LCM across the whole list, ignoring order.
What about zero and negatives?
Signs are ignored. A list of only zeros has GCD 0 and no finite LCM, which is reported.
Is any data sent away?
No. The arithmetic runs entirely in the page.
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