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GCD & LCM Calculator
Calculate Greatest Common Divisor (GCD/HCF) and Least Common Multiple (LCM) for two or more numbers. Step-by-step. 100% private. 100% free and private.
Free GCD & LCM Calculator
Find the Greatest Common Divisor (GCD or HCF) and Least Common Multiple (LCM) of two or more positive integers. Useful for simplifying fractions, ratio problems, and scheduling.
Common Uses
Simplify fractions to lowest terms
Solve word problems on ratios and proportion
Plan repeating schedules and cycles
Verify number theory homework
Demonstrate the Euclidean algorithm
How It Works
GCD is computed with the Euclidean algorithm: gcd(a,b) = gcd(b, a mod b). For more than two numbers we reduce pairwise. LCM uses the identity lcm(a,b) = a*b / gcd(a,b), again reduced across the list.
Privacy
All computation is local. Your numbers stay on your device.
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LCM From GCD
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