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GCD & LCM Calculator

Find the greatest common divisor and lowest common multiple of any set of numbers.

To find the GCD and LCM, enter two or more whole numbers separated by commas. The greatest common divisor is computed with the Euclidean algorithm and the lowest common multiple is derived from it, along with the simplified ratio of your inputs.

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Frequently asked questions

What is the Euclidean algorithm?

Repeatedly replace the larger number with its remainder when divided by the smaller, until one becomes zero; the other is the greatest common divisor. It dates to around 300 BC and remains the fastest method known for ordinary integers.

How are GCD and LCM related?

Their product equals the product of the two original numbers. So once you have the GCD, the LCM is simply a × b ÷ GCD — which is far cheaper than searching for the lowest common multiple directly.

How to use the gcd & lcm calculator

  1. 1Enter or paste your numbers.
  2. 2The result appears immediately — copy or download it.

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