LCM Calculator

Least Common Multiple of up to 5 numbers

LCM is the smallest positive integer that is divisible by each of the numbers.
Narendra Kumar
Created by
Narendra Kumar
 Reema Singh
Verified by
Reema Singh
Last Updated: 15-02-2026

LCM Calculator - Least Common Multiple

The Least Common Multiple (LCM) is the smallest positive number divisible by two or more numbers without a remainder. It is commonly calculated using multiples, prime factorization, or the LCM formula based on GCD.

LCM can also be calculated using the formula:LCM(a, b) = (a × b) ÷ GCD(a, b), where GCD is also known as HCF (Highest Common Factor).

For Example: Find the LCM of 12 and 16.
Multiples of 12: 12, 24, 36, 48, 60, 72, 84, 96, 108, 120 ...
Multiples of 16: 16, 32, 48, 64, 80, 96, 112, 128, 144, 160...
So the common multiples of 12 and 16 are 48, 96, ..., but the smallest of these is 48. So, LCM(12, 16) = 48.

Take another example with division method
  1. Write the numbers side by side.
  2. Divide them by a prime number that divides at least one of the numbers.
  3. Write the quotients below.
  4. Repeat until no two numbers have a common divisor greater than 1.
  5. Multiply all the divisors and the final quotients to get the LCM.

Example 3

Find the LCM of number 20, 30, and 50.

| 2 | 20, 30, 50 |
| 2 | 10, 15, 25 |
| 3 | 5, 15, 25 |
| 5 | 5, 5, 25 |
| 5 | 1, 1, 5 |

Now, multiply the divisors: 2×2×3×5×5=3002 \times 2 \times 3 \times 5 \times 5 = 300.
So, LCM(20, 30, 50) = 300.

How it works

  1. Enter 2, 3, or 4 numbers in the input fields.
  2. Click the "Calculate LCM" button.
  3. The LCM and the calculation process will be displayed on the right side.

Example Calculation

Input: Number 1 = 12 , Number 2 = 15, Number 3 = 20

Calculation: LCM(12, 15) = 60, LCM(60, 20) = 60

Output: LCM: 60 Formula: LCM(12, 15, 20) = LCM(12, 15) = 60, LCM(60, 20) = 60

In the image below, we can see how to calculate the LCM with the division method.

Example of Lcm Least Common Multiple calculation

This video explains how to calculate LCM using our free LCM calculator. Watch the steps and try it yourself using the tool below.

FAQ on LCM Calculator

1. What is the easiest way to find LCM?

The division (prime factorization) method is the fastest and most reliable way.

2. Can LCM be smaller than the numbers?

No, the LCM is always greater than or equal to the largest number.

3. What is the difference between LCM and HCF?

LCM finds the smallest common multiple, while HCF finds the greatest common divisor.

4. Can LCM be calculated for more than two numbers?

Yes, LCM can be calculated for any number of integers.