LCM Function - Least Common Multiple


The LCM function returns the lowest common multiple of integers.  As part of some of your math classes you no doubt had to compute the Lowest common multiple or the Greatest common divisor.  Ah, if you had only known that Excel could do that for you.

Some people call LCM the least common multiple and others call it lowest common multiple.

The Syntax for the LCM function is:
   =LCM(number1,[number2],…)

Number1 is required, the other numbers are optional.

There can be from 1 to 255 numbers.  If a number is not an integer the decimal portion is dropped.
If any argument is nonnumeric, the function returns a #VALUE! error.
If any argument is less than zero, the function returns a #NUM! error.

The lowest common multiple is the smallest positive integer that is a multiple of all integer arguments number1, number2, and so on.  The least common multiple for the fractions being added below is 42.
     1/6 + 3/21 + 2/7
Six, twenty-one and seven all divide evenly into 42. 

Results from the LCM function
Formula    Result Description
=LCM(2,4) 4
=LCM(3,6,8) 2424 can be divided evenly by 3, 6 or 18
=LCM(1,3,13,22)  858858 can be divided evenly by 1, 3, 13, or 22
=LCM(2.8,4) 4The fraction portion is dropped. The value 2.8 is treated as 2.
=LCM(-3,5) #NUM!  The negative value creates an error that Excel displays as #NUM!