The Least Common Multiple (LCM) is the smallest number that is a multiple of two or more numbers.
To calculate the LCM, you need to list all of the multiples of the numbers that you are trying to find the LCM for. Then, find the smallest number that is a multiple of all of the numbers that you listed.
For example, if you are trying to find the LCM of 12 and 15, you would list all of the multiples of 12 and 15. The multiples of 12 are 12, 24, 36, 48, 60, and 72. The multiples of 15 are 15, 30, 45, 60, 75, and 90. The smallest number that is a multiple of both 12 and 15 is 60. Therefore, the LCM of 12 and 15 is 60.
 | = | least common multiple |
 | = | greatest common divisor |
 | = | non-zero integers |
Example 2: Find the LCM of 15 and 30.
The LCM of 15 and 30 is 15. The LCM is the smallest number that is a multiple of both 15 and 30.