GCD Calculator
Greatest common divisor.
Enter the values and press Calculate.
How to use GCD Calculator
The greatest common divisor is the largest integer dividing both numbers. This tool finds it step by step.
Open GCD Calculator on toolpermarket. It runs entirely in your browser, so you can start without creating an account.
Enter the two integers a and b in the fields above, then press Calculate.
Read the result below the form. Change any input and run it again as many times as you like — the math is instant and local.
Worked example. The GCD of 12 and 18 is 6.
When to use GCD Calculator. Use it to simplify fractions, scale ratios, or solve divisibility problems.
Frequently asked questions
Is GCD Calculator free to use?
Yes. GCD Calculator runs entirely in your browser. There is no account, no upload, and no cost.
Does GCD Calculator work on mobile?
Yes. The layout is responsive, so GCD Calculator works on any phone, tablet, or desktop with a modern browser.
What if one number is zero?
The GCD of 0 and b is the absolute value of b, since every number divides 0.
Are negative inputs allowed?
Yes. The tool uses absolute values, so the sign does not change the result.