GCD and LCM Calculator
Greatest common divisor and least common multiple.
Input
This tool runs entirely in your browser. The data you paste or load is never uploaded.
Result
Enter your input, then run the tool.
About this tool
Finds the greatest common divisor and least common multiple of two or more whole numbers, with the prime factorisation of each so you can see where the result comes from. Handles very large integers exactly.
How to use it
- Enter two or more whole numbers separated by commas or spaces.
- Press Calculate.
- Read the GCD, the LCM and each number’s prime factors.
Frequently asked questions
What is the GCD used for?
Simplifying fractions: divide the numerator and denominator by their GCD. 18/24 has a GCD of 6, so it becomes 3/4.
And the LCM?
Finding a common denominator, or when two cycles line up again: buses every 12 and 18 minutes meet every 36 minutes.
Keep going
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