Syntax. LCM(number1,number2;...)
Definition. This function returns the least common multiple of integers. The least common multiple is the smallest positive integer that is a multiple of all integer arguments (number1, number2, and so on). Use LCM() to add fractions with different denominators.
Arguments
number1 (required) and number2 (optional) The minimum number of values is 1, and the maximum is 255 (29 in Excel 2003 and earlier versions) for which you want the least common multiple. At least one value is required but a second value makes sense so that a least common multiple can be found.
Background. For example, the least common multiple is used to add fractions. The least common multiple is the smallest integer that is a multiple of number1 (m) and number2 (n).
Excel calculates the least common multiple based on integers. Decimal places are truncated. If one of the arguments isn’t a numeric expression, the LCM() function returns the #VALUE! error. If one of the arguments is smaller than zero, the function returns the #NUM! error.
Like the greatest common divisor, the least common multiple can be calculated by factorizing m and n. Examples include:
m = 36 = 22 • 32
n = 120 = 23 • 3 • 5
All prime factors are multiplied:
23 • 32 • 5 = 360
Note
The greatest common divisor can be calculated from the least common multiple and the product of m and n (see the GCD() function).
Example. Two people run next to each other. The step length of one runner is 1.10 m and the other runner takes 1.43 m steps. Both runners start at the same time. After what distance do the runners tread simultaneously?
=LCM(110,143)
returns 1430; that is, both runners tread simultaneously after 14.30 m.