GCF and LCM Calculator
Greatest common factor and least common multiple, with prime factors.
Reviewed by James Whitfield · How we check our maths
Your values
ⓘ Live results
Results
- Greatest common factor
- 12
- Least common multiple
- 360
- Product of all numbers
- 51,840
| Number | Prime factorisation |
|---|---|
| 24 | 2 × 2 × 2 × 3 |
| 36 | 2 × 2 × 3 × 3 |
| 60 | 2 × 2 × 3 × 5 |
Quick answer
The GCF is the largest number dividing all inputs; the LCM is the smallest number all inputs divide into.
The formula
LCM(a,b) = a × b ÷ GCF(a,b)
Worked example
Worked example
Using the values the calculator loads with.
Inputs
- Numbers (comma separated)24, 36, 60
Result
- Greatest common factor12
- Least common multiple360
- Product of all numbers51,840
How to use the GCF and LCM Calculator
- 1Type your numbers separated by commas.
- 2Read the GCF and LCM.
- 3Check the prime factorisation table for the working.
Frequently asked questions
When do I need the LCM?
Adding fractions with different denominators, and scheduling problems where two cycles must line up.
What if the GCF is 1?
The numbers are coprime — they share no common factor, and their LCM is simply their product.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error