HCF Calculator

Enter two or more positive integers to calculate their Highest Common Factor (HCF), also called Greatest Common Divisor (GCD).

Introduction

The HCF (Highest Common Factor) of two or more numbers is the largest number that divides all of them exactly. It’s useful in simplifying fractions and solving number problems.

How it Works

Factorization method: List factors of each number and take the largest common one.
Euclidean algorithm: Repeated division until the remainder is 0. Last divisor = HCF.

HCF Formula: HCF(a, b) = HCF(b, a mod b)

Examples

HCF of 18 and 27: Common factors → 1, 3, 9. HCF = 9.

HCF of 20, 50, 120: Common factors → 1, 2, 5, 10. HCF = 10.

FAQs

The HCF is the greatest number that divides all given numbers exactly. It is also called the Greatest Common Divisor (GCD).