Free & Instant
GCD Calculator
Find the Greatest Common Divisor of two or more numbers instantly.
GCD Calculator
Calculate the greatest common divisor instantly.
Separate numbers with commas
Greatest Common Divisor
0What is GCD?
The Greatest Common Divisor (GCD), also called the Greatest Common Factor (GCF), is the largest number that divides evenly into all the given numbers without leaving a remainder.
GCD Method (Euclidean Algorithm)
GCD(a, b) = GCD(b, a mod b), until b = 0
Example: GCD(24, 36) = 12
Frequently Asked Questions
Can I find the GCD of more than two numbers?
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Yes, simply enter all numbers separated by commas, and the calculator will find the GCD across all of them.
Where is GCD commonly used?
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GCD is used to simplify fractions, solve problems involving equal grouping, and in cryptography algorithms like RSA encryption.
What if the numbers have no common factor besides 1?
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If the GCD is 1, the numbers are called "coprime" or "relatively prime" — they share no common factors other than 1.