โ Math
GCD Calculator
The greatest common divisor is the largest number that divides evenly into every value in the set. It is the key step in reducing fractions and in certain cryptography algorithms.
How it works
First number
Second number
Third number (optional)
Greatest common divisor
Least common multiple
Are they coprime
Frequently asked questions
How do I use the GCD Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.