GCD and LCM Calculator
Find the greatest common divisor and the least common multiple of two whole numbers.
Results
Greatest common divisor
12
Least common multiple
72
What this tool does
The greatest common divisor is the largest number that divides both values exactly, which is what simplifies a fraction to its lowest terms. The least common multiple is the smallest number both divide into, which is what you need to add fractions or to find when two repeating cycles coincide.
Formula
lcm(a, b) = |a × b| ÷ gcd(a, b)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
a | First value | — |
b | Second value | — |
g | Greatest common divisor | — |
l | Least common multiple | — |
Worked example
- First value24
- Second value36
- Greatest common divisor12
- Least common multiple72
Limitations
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.