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GCF Calculator

Find the greatest common factor of whole numbers.

Whole numbers is required.

Press Calculate, or Enter in any field.

GCF of 12, 18, and 30

Their greatest common factor is 6.

Complete the required fields to see the result.

What this calculator does

Enter an integer list to calculate its greatest common factor using normalized absolute values.

Inputs and what they mean

Whole numbers
text value.

How to use it

  1. Enter the requested values.
  2. Choose the calculation mode when available.
  3. Review the result and supporting breakdown.

Formula

The GCF is found by repeatedly applying Euclid’s greatest-common-divisor algorithm.

Worked example

GCF of 12, 18, and 30

Their greatest common factor is 6.

Reading the result

The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.

Limitations and assumptions

Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.

Common questions

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