Least common multiple (LCM) is also known Lowest Common Multiple or smallest common multiple. This online Calculator help us to evaluate LCM of any two numbers. Let $a$ and $b$ be any two numbers, the LCM of $a$ and $b$ is a smallest positive number which can be divided by both $a$ and $b$ without giving any remainder.
Steps to find the least common multiple of 12 and 18.

Step 1 : Divide 2 from number until it won't be able to go with it.

Ladder Method LCM

Step 2 : Divide 3 from number until it won't be able to go with it and continue this method until the reminder is 1.

LCM Ladder Method   
Step 3 : The prime factorization of 12 and 18 is $2 \times 2 \times 3 \times 3$ or $2^{2} \times 3^{2}$.

Step 4 :  LCM = $2 \times 2 \times 3 \times 3$ = 36