How to find the least common multiple
Factor each input into primes. For each prime appearing anywhere in the list, keep its highest exponent; multiply those prime powers. This produces the smallest positive number divisible by all the inputs.
For two positive integers, LCM(a, b) = (a ÷ GCF(a, b)) × b. Apply that operation repeatedly for a longer list. The calculator checks safe integer precision rather than presenting a rounded large integer as exact.
Example: 12, 18 and 30
12 = 2² × 3, 18 = 2 × 3², and 30 = 2 × 3 × 5. Keeping the highest powers gives 2² × 3² × 5 = 180. Check the result: 180 ÷ 12 = 15, 180 ÷ 18 = 10, and 180 ÷ 30 = 6.
Common denominators and repeating events
An LCM supplies a common denominator when adding fractions. For events repeating every 12 and 18 days from the same starting point, the first shared repeat is after 36 days. If starting times differ, the LCM alone does not determine the next coincidence.
Enter 2–100 non-zero integers with magnitudes at most 10¹². Negative signs are ignored. Zero is excluded because this tool seeks a positive common multiple. Decimal or invalid entries cause the whole list to be rejected.