🤝 Common Factor Calculator
Common factors are the numbers that divide evenly into both of your inputs — for 12 and 18 that is 1, 2, 3 and 6. The calculator finds them by first computing the greatest common factor with Euclid's algorithm, then listing its divisors.
The greatest common factor is the star of the show: it reduces fractions to lowest terms, splits quantities into the largest equal groups, and sits at the heart of the least common multiple.
How to use this calculator
Enter two integers and press Calculate to list every factor they share, with the greatest one highlighted.
- Type the first integer.
- Type the second integer.
- Press Calculate.
- Read the full list of common factors and the greatest common factor.
Frequently asked questions
What does this common factor calculator compute?
It finds the greatest common factor of your two integers with Euclid's algorithm, then lists every divisor of it, which is exactly the set of factors the two numbers share.
Can you show a worked example?
For 12 and 18 the common factors are 1, 2, 3 and 6, and the greatest common factor is 6.
What if one number is zero?
Every divisor of the other number also divides zero, so the common factors of 0 and 5 are 1 and 5. Both inputs being zero is rejected since every integer would qualify.
How is the greatest common factor used?
It reduces fractions to lowest terms, for example 12/18 becomes 2/3, and it finds the largest equal group size when splitting quantities fairly.