LCM of three or more numbers
Combine a group of integers without guessing a large shared multiple.
By the ClearLCM team · Updated November 3, 2026
Work from left to right
For 12, 18 and 24, first compute LCM(12, 18) = 36. Next compute LCM(36, 24). The GCF of 36 and 24 is 12, so (36 ÷ 12) × 24 = 72. The final answer is 72. Check it by division: 72 ÷ 12 = 6, 72 ÷ 18 = 4 and 72 ÷ 24 = 3. Each is a whole number.
Why combining pairs works
Any multiple shared by all three original numbers must be a multiple of the LCM of the first two. Combining that intermediate LCM with the third therefore preserves the common-multiple requirement. The same approach works for longer lists. Duplicate inputs do not change the final LCM: adding another 12 to this example still gives 72. The order of inputs does not change the mathematical result, though the intermediate steps can look different.
Enter and verify the whole list
Separate numbers using commas, spaces, semicolons or new lines. ClearLCM accepts up to 50 integers with up to 20 digits each. Large inputs can produce a long answer; the tool uses exact integer arithmetic rather than rounding it into scientific notation. Read the pairwise steps below the result, then copy or download them if you need to keep the calculation. Changing the input clears the old result until you calculate again.
Put the example into practice with the free least common multiple calculator.