GCF Calculator

Find the greatest common factor of two or more numbers.

GCF & LCM Calculator

Enter 2 to 6 numbers

GCF

LCM

Prime Factorizations

Enter your numbers above and tap Calculate GCF & LCM to see the results.

Step-by-step Solution

Formulas

GCF: Largest number that divides all inputs
LCM: Smallest number divisible by all inputs
Relation: GCF(a,b) × LCM(a,b) = a × b

Tips

GCF is useful for simplifying fractions to lowest terms.

LCM is used to find common denominators when adding fractions.

Prime factorization helps find GCF and LCM efficiently.

Related Calculators

Pro Tips

Results update as you type — change any field to see the effect immediately.

Check that every value uses the same unit before comparing results.

Use the copy button to paste the gcf figures into a note or spreadsheet.

Nothing is sent to a server, so you can use this with private figures.