Greatest Common Factor (GCF / HCF / GCD) Studio
Find Greatest Common Factor • Highest Common Factor (HCF) • Greatest Common Divisor (GCD) • Detailed Educational Steps
Greatest Common Factor Suite
Supports up to 100 numbers. Enter any numbers below 1 Billion to calculate.
Step-by-Step Mathematical Proofs
Understand how the GCF is computed using two standard educational methods.
Method 1: Listing Factors
Write down all positive factors for each number. Find the largest factor shared by all numbers.
Method 2: Prime Factorization
Decompose each number into its prime components. Identify the common prime factors and multiply their lowest powers.
GCF Quick Reference Sheet
Click any row to load the values into the analyzer.
| Number Pair / Set | GCF Result | Classification | Action |
|---|---|---|---|
| 12, 18 | 6 | Even Divisor | |
| 24, 36 | 12 | Even Divisor | |
| 15, 20 | 5 | Odd Divisor | |
| 32, 48 | 16 | Even Divisor | |
| 14, 28, 42 | 14 | Even Divisor | |
| 25, 75 | 25 | Odd Divisor | |
| 10, 20, 30 | 10 | Even Divisor | |
| 9, 27 | 9 | Odd Divisor | |
| 11, 13 | 1 | Coprime Set | |
| 60, 90 | 30 | Even Divisor |
Overview & Capabilities
Calculate the Greatest Common Factor (GCF), Highest Common Factor (HCF), or Greatest Common Divisor (GCD) with our Euclidean Algorithm Studio! Find the largest shared integer divisor across multiple numbers with step-by-step division remainder tables, common divisor sets, and coprime verification.
How to Use
Key Features
Common Use Cases
Tips & Best Practices
Frequently Asked Questions
Q What makes Euclid's division algorithm so efficient for large numbers?
Instead of factoring huge numbers, Euclid's algorithm replaces numbers with their division remainders: GCF(a, b) = GCF(b, a mod b). The numbers shrink exponentially with each step, finding the divisor in logarithmic time.
Q What is an HCF vs GCD vs GCF?
They are identical mathematical terms: GCF (Greatest Common Factor, US), HCF (Highest Common Factor, UK/Commonwealth), and GCD (Greatest Common Divisor, abstract algebra).
Q What is the GCF of any number and 0?
GCF(n, 0) = |n| for any non-zero integer n, because every integer divides 0 (since n × 0 = 0), making |n| the largest shared divisor.


