GCF Calculator

Free online GCF calculator to find the greatest common factor of two or more numbers. Calculate GCF with step-by-step explanation and examples.

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How to Calculate GCF?

The Greatest Common Factor (GCF), also known as the Greatest Common Divisor (GCD), is the largest positive integer that divides two or more numbers without leaving a remainder. It's useful for simplifying fractions and solving various mathematical problems.

Finding GCF of Multiple Numbers:

  • Find the GCF of the first two numbers
  • Use that result to find the GCF with the next number
  • Continue until all numbers are processed

GCF(12, 18, 24) = 6

Finding GCF using Prime Factorization:

  • Find the prime factors of each number
  • Identify the common prime factors
  • Multiply the common prime factors with the lowest exponents

48 = 2⁴ × 3

60 = 2² × 3 × 5

GCF(48, 60) = 2² × 3 = 12

Common GCF examples

Numbers GCF
12, 18 6
24, 36 12
15, 25 5
8, 12, 16 4
20, 30, 40 10
7, 11 1
100, 200 100