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Common Factor Calculator
About the Common Factor Calculator
List every common factor of two numbers and find the greatest common factor (GCF).
How to use the Common Factor Calculator
- Enter the First Number and Second Number, or click one of the examples.
- Press Find Common Factors.
Formula and method
A common factor is a whole number that divides both numbers with no remainder. The greatest of them is the GCF.
Worked example
48 and 36 have the common factors 1, 2, 3, 4, 6 and 12, so the GCF is 12. 13 and 17 are coprime: their only common factor is 1.
Tips
- Use the GCF to simplify fractions: divide numerator and denominator by it.
- Two numbers with a GCF of 1 are called coprime.
Frequently Asked Questions
Factors divide a number exactly. Multiples are what you get by multiplying it.