GCD & LCM Calculator
Greatest common divisor and least common multiple of any numbers. Find the GCD (HCF) and LCM of two or more numbers instantly. Step-count shown via the Euclidean algorithm. Free online GCD and LCM calculator.
About the GCD & LCM Calculator
The greatest common divisor (or highest common factor) is the largest number dividing all your inputs exactly; the least common multiple is the smallest number they all divide into. These two values power fraction simplification, gear-ratio problems and scheduling cycles — "when do two blinking lights sync?". Enter two or more integers and this calculator returns both results with the count of Euclidean algorithm steps used to find them.
How to use the GCD & LCM Calculator
- Enter your numbers separated by commas.
- Results appear instantly.
- Use the GCD to simplify fractions.
- Use the LCM to combine denominators or cycles.
Key features
- GCD/HCF and LCM together
- Two or more numbers at once
- Uses the efficient Euclidean algorithm
- Accepts negative and large integers
What is the Euclidean algorithm?
How are GCD and LCM related?
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