What is the GCD Calculator?
ToolsPopper's GCD Calculator finds the greatest common divisor (GCD) — also called the highest common factor (HCF) — of two integers using the Euclidean algorithm. Enter A and B, click Calculate, and get the largest positive integer that divides both numbers evenly.
Computation runs entirely in your browser. Whether you are simplifying fractions, solving number-theory homework, or checking RSA exercises, your inputs stay private on your device.
When to use a GCD calculator
- Fraction simplification — divide numerator and denominator by their GCD
- Algebra homework — find common factors of polynomial coefficients
- Number theory — explore coprime pairs where GCD equals 1
- Scheduling problems — align repeating cycles using shared divisors
How the GCD Calculator works
The Euclidean algorithm repeatedly replaces the larger number with the remainder of division until the remainder is zero. The last non-zero remainder is the GCD. The tool handles negative inputs by using absolute values in the result.
How to calculate GCD
- Enter the first integer in field A.
- Enter the second integer in field B.
- Click Calculate to see the greatest common divisor.
- Try new pairs — unlimited calculations.
ToolsPopper vs CalculatorSoup GCD and Wolfram Alpha
- Two-field focused UI — no navigating a full scientific keypad
- Unlimited free calculations — no query throttling
- Private local Euclidean math — integers never sent to a server
- No signup — calculate immediately
- Clear numeric output — one GCD value, easy to copy