Greatest Common Factor Calculator
Find the greatest common factor (GCF/GCD) of a list of integers together with the step-by-step factorization.
Runs 100% in your browser — nothing is uploaded.
Result
Formula
GCF is the largest integer that divides every input.
About this calculator
The Greatest Common Factor (GCF) Calculator finds the largest positive integer that divides each of the given numbers without leaving a remainder. It also provides the prime factorization of the result to illustrate the underlying math.
How to use
- 1
Enter two or more integers separated by commas in the “Numbers” field (e.g., 12, 18).
- 2
Click the Calculate button to compute the greatest common factor.
- 3
Review the result and the prime factorization of the GCF shown below.
Frequently asked questions
What is the difference between GCF and GCD?
GCF stands for Greatest Common Factor, and GCD stands for Greatest Common Divisor. They are the same concept: the largest positive integer that divides two or more numbers without a remainder.
Can I enter more than two numbers?
Yes, you can enter any number of positive integers separated by commas, spaces, or semicolons. The calculator will find the GCF of all of them.
What if I enter a zero or a negative number?
The calculator only accepts positive integers. Zero and negative numbers will cause an error message. Please enter positive integers only.
Please note: Results are estimates for general information only and are not professional or medical/financial advice.