GCD/HCF Calculator

⚡ Find GCD/HCF instantly with step-by-step solutions. Works with 2, 3, or 4 numbers. 100% free.

The Best GCD/HCF Calculator Online

Our GCD calculator is designed for students who want to actually understand math. We show you the complete Euclidean algorithm step-by-step, so you actually LEARN - not just get answers. The Greatest Common Divisor (GCD), also known as the Highest Common Factor (HCF), is essential for simplifying fractions and solving ratio problems. No signup, no ads, just instant accurate results.

Euclidean Algorithm

GCD(a, b) = GCD(b, a mod b)

The most efficient method to find GCD

Prime Factorization

GCD = Product of common prime factors

Find GCD by identifying common prime factors

Examples

GCD of 48 and 18

148 = 2 × 24 = 2 × 2 × 12 = 2⁴ × 3
218 = 2 × 9 = 2 × 3²
3Common factors: 2 × 3 = 6
4GCD(48, 18) = 6

GCD of 24, 36, 48

124 = 2³ × 3
236 = 2² × 3²
348 = 2⁴ × 3
4Common: 2² × 3 = 12
5GCD = 12

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Frequently Asked Questions

What is the difference between GCD and HCF?

GCD (Greatest Common Divisor) and HCF (Highest Common Factor) are the same thing. GCD is more commonly used in the US, while HCF is used in the UK and India.

How do you find GCD of two numbers?

You can find GCD using the Euclidean algorithm (repeatedly divide and take remainder) or by finding prime factorizations and multiplying common factors.

What is GCD of 0 and any number?

The GCD of 0 and any number n is n itself, because every number divides 0.