Find the least common multiple (LCM) of two or more whole numbers, with the prime factorization of each number and their greatest common factor.
About this tool
Find the least common multiple of two or more numbers, with prime factorization steps.
How to use LCM Calculator
- Enter two or more whole numbers separated by commas or spaces.
- Read the LCM at the top.
- Check the prime factors to see how it is built.
Worked example
Buses leave every 12, 18 and 30 minutes. The LCM of 12, 18 and 30 is 180, so they all leave together every 3 hours.
How is the LCM found?
Take every prime factor at its highest power in any number: 12 = 2² × 3, 18 = 2 × 3², 30 = 2 × 3 × 5, so LCM = 2² × 3² × 5 = 180.
Where is the LCM used?
Finding common denominators for fractions and scheduling repeating events are the most common uses.
- LCM Calculator — Find the least common multiple of two or more numbers, with prime factorization steps.
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