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Percentage Calculator
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GCF Calculator
Find the greatest common factor (GCF) of two or more whole numbers, with the Euclidean steps and the LCM.
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What is the GCF?
The greatest common factor (also called greatest common divisor, GCD, or highest common factor, HCF) is the largest whole number that divides every number in the set. GCF(24, 36) = 12.
Euclidean algorithm
Divide the larger number by the smaller and keep the remainder. Repeat with the smaller number and the remainder until the remainder is 0. The last non-zero remainder is the GCF. For several numbers, apply it pairwise: GCF(a, b, c) = GCF(GCF(a, b), c).
LCM(a, b) = a × b ÷ GCF(a, b)
Simplifying fractions: divide top and bottom by their GCF (24/36 → 2/3).
Frequently asked questions
What is the GCF of 12 and 18?
6.
What is the GCF of 24 and 36?
12.
About this tool
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- Formula tests passed · human review pending
- Last updated
- 31 Oct 2026
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