### Least Common Multiple or Greatest Common Divisor

Go to Norwegian version
How to calculate the **least common multiple** (lcm) and the **greatest common divisor** (gcd) of two numbers:

**Difficult way**: To find either the least common multiple (lcm) or greatest common divisor (gcd), is also known as the greatest common divisor (gcf) of two numbers, you always start out the same way: you find the prime factorizations of the two numbers.
Then you put the factors into a nice neat grid of rows and columns, compare and contrast, and then, from the table, take only what you need.

**Easy way**: Use the calculator below.