How to use the Least Common Multiple Calculator
The LCM calculator finds the smallest number that is a multiple of every number in a list.
Open the Least Common Multiple Calculator →
What you need to enter
- Whole numbers
The formula
LCM(a, b) = a × b ÷ GCF(a, b); repeat for more numbers.
Worked example
Using the default values in the calculator:
- Whole numbers: 12, 18, 30
| LCM | 180 |
| GCF | 6 |
Tips for better results
- Use it to add fractions with different denominators.
- Whole numbers only.
Common mistakes to avoid
- Using the product instead of the LCM.
- Entering decimals.