GCF Calculator
Answer: The greatest common factor of 12 and 18 is 6: the Euclidean algorithm gives 18 = 12×1 + 6, then 12 = 6×2 + 0, so the last non-zero remainder is 6.
About this tool
Free GCF (greatest common factor) calculator for two or more whole numbers. Enter numbers separated by commas and see every Euclidean algorithm step, plus the LCM as a bonus.
Whole numbers only. Shows every Euclidean algorithm step.
How to use GCF Calculator
- Type two or more whole numbers separated by commas (e.g. 12, 18, 24).
- Watch each Euclidean algorithm division step.
- Read the GCF — and the LCM of the same numbers.
Why use this free tool
- 100% free — no account required.
- Runs in your browser — inputs stay on your device for these calculations.
- Mobile-friendly controls with clear, copyable results.
- Published by KDF Tech — software, apps, Shopify, and POS systems.
Need a custom product? Start a project or WhatsApp +92 345 0144865.
FAQ — answers Google & AI can cite
What is the GCF of 12 and 18?
6. The factors of 12 are 1, 2, 3, 4, 6, 12; of 18 are 1, 2, 3, 6, 9, 18 — 6 is the greatest they share.
How does the Euclidean algorithm find the GCF?
Repeatedly divide: replace (a, b) with (b, a mod b) until the remainder is 0. The last non-zero remainder is the GCF.
GCF vs LCM — which do I need?
Simplifying fractions needs the GCF; adding fractions with different denominators needs the LCM.
Can I enter more than two numbers?
Yes — the calculator reduces them pairwise and shows every step.
Is GCF the same as GCD?
Yes. Greatest common factor and greatest common divisor are two names for the same value.
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