GCD & LCM Calculator

Enter two numbers to calculate the greatest common divisor (GCD) and least common multiple (LCM). Handy for solving math problems — all calculations happen inside your browser.

Enter two numbers to see the result.

How to use

  1. Enter the first number.
  2. Enter the second number.
  3. The GCD and LCM are shown in real time.

Frequently asked questions

How do I find the GCD?

The greatest number that divides both numbers evenly is the greatest common divisor. This calculator finds it quickly using the Euclidean algorithm.

How do I find the LCM?

The least common multiple is the smallest common multiple of the two numbers, equal to their product divided by the GCD.

Are the values I enter sent to a server?

No. All calculations happen only inside your browser, and the values you enter are never sent to or stored on any server.