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GCD & LCM Calculator

Calculate the Greatest Common Divisor (GCD) and Least Common Multiple (LCM) of two or more numbers.

Number 1
Number 2

Greatest Common Divisor (GCD)

The GCD (also known as the Greatest Common Factor or GCF) is the largest positive integer that divides each of the numbers without a remainder. For example, the GCD of 12 and 18 is 6, because 6 is the largest number that divides both 12 and 18 evenly.

The GCD is useful for simplifying fractions, finding equivalent ratios, and solving problems involving divisibility.


Least Common Multiple (LCM)

The LCM is the smallest positive integer that is divisible by each of the numbers. For example, the LCM of 4 and 6 is 12, because 12 is the smallest number that both 4 and 6 divide into evenly.

The LCM is useful for adding and subtracting fractions with different denominators, finding common time intervals, and solving scheduling problems.


Relationship Between GCD and LCM

For any two positive integers a and b, there's a useful relationship: GCD(a, b) × LCM(a, b) = a × b

This relationship can be used to calculate one value when you know the other.


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