LCM and GCD (HCF) Calculator
Find the least common multiple and greatest common divisor of any numbers.
The GCD (greatest common divisor, also called HCF) is the largest number that divides all of them; the LCM (least common multiple) is the smallest number they all divide into. Both use the Euclidean algorithm. Runs in your browser.
Enter two or more whole numbers to find their LCM (least common multiple) and GCD (greatest common divisor, also called HCF — highest common factor). Both are computed with the fast Euclidean algorithm. Useful for fractions, scheduling and number-theory homework. Runs in your browser.
How to use the LCM & GCD Calculator
- Enter two or more whole numbers, separated by commas or spaces.
- Read the GCD (HCF) and the LCM.
- Use them for reducing fractions or finding common denominators.
Frequently asked questions
What's the difference between LCM and GCD?
The GCD (or HCF) is the largest number that divides all your numbers evenly. The LCM is the smallest number that all of them divide into evenly. They're related: for two numbers, LCM × GCD = the product of the numbers.
Is HCF the same as GCD?
Yes. HCF (highest common factor) and GCD (greatest common divisor) are two names for the same thing.