LCM & GCD Calculator
Find the least common multiple and greatest common divisor of a set of integers.
How to use LCM & GCD Calculator
Three quick steps — no sign-up needed
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Step 1
Enter the integers
Type whole numbers separated by commas or spaces.
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Step 2
Calculate LCM and GCD
Run the tool to find least common multiple and greatest common divisor (HCF).
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Step 3
Use the results
Apply LCM to matching denominators or schedules; use GCD to simplify ratios and fractions.
About LCM & GCD Calculator
LCM & GCD Calculator finds the least common multiple and greatest common divisor (also called HCF) for a list of integers. Students searching "LCM calculator", "GCD calculator", or "HCF online" often need both values for fraction and number-theory exercises.
Enter integers separated by commas or spaces. GCD is the largest positive integer dividing all of them; LCM is the smallest positive integer that is a multiple of each. Zero and negative inputs follow standard integer definitions used by the implementation - prefer positive integers for school problems.
Show Euclidean-algorithm working when your course requires it; use this page to verify.
Integer number-theory helper for education and quick checks.
Benefits of LCM & GCD Calculator
Frequently asked questions
What is GCD (HCF)?
The greatest common divisor - largest positive integer that divides each number in the set.
What is LCM?
The least common multiple - smallest positive integer that is a multiple of each number.
Can I enter more than two numbers?
Yes - provide a full list separated by commas or spaces.
Does order matter?
No for LCM and GCD.
Is this a proof tool?
It computes values; proofs still use the Euclidean algorithm on paper when required.