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GCD & LCM Calculator

Fundamental number theory.

Interactive Tool
Live Calculation

GCD & LCM Calculator

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Evaluated Formula:undefined
Guidance:
GCD of two coprime numbers is always 1.
LCM is used for adding fractions with different denominators.
GCD
1

Calculated instantly

LCM216

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What This Calculator Does

The GCD & LCM Calculator finds the Greatest Common Divisor and Least Common Multiple of two or more integers. GCD is the largest number that divides all given numbers without a remainder.

How It Works

GCD uses the Euclidean algorithm: repeatedly replace the larger number by the remainder of dividing the larger by the smaller. LCM = |a x b| / GCD(a, b).

Example

For 12 and 18: GCD = 6, LCM = (12 x 18) / 6 = 36.

Formula

Euclidean
LCM(a,b) = |a*b| / GCD(a,b)

Reading the Results

GCD

The greatest number that divides both A and B evenly.

LCM

The smallest number that is a multiple of both A and B.

Frequently Asked Questions

What is GCD?

The Greatest Common Divisor is the largest positive integer that divides two or more integers without a remainder.

What is LCM used for?

LCM is used when finding common denominators for fractions, scheduling recurring events, and solving gear-ratio problems.

Can GCD work with more than 2 numbers?

Yes. GCD(a,b,c) = GCD(GCD(a,b),c). Apply the algorithm iteratively.