Least Common Multiple Calculator

LCM equals a times b divided by GCD of a and b

Solution

Share:

How It Works

The Least Common Multiple is the smallest positive integer divisible by both numbers. This calculator finds the GCF first using Euclid's algorithm, then computes LCM(a, b) = (a × b) / GCF(a, b). The LCM is essential for adding fractions with different denominators.

Example Problem

Find LCM(12, 18):

  1. GCF(12, 18) = 6
  2. LCM = (12 × 18) / 6 = 216 / 6 = 36

Frequently Asked Questions

How to find the LCM of two numbers?

The fastest method is to find the GCF first (using Euclid's algorithm), then divide the product of the two numbers by the GCF. For 8 and 12: GCF = 4, LCM = (8 × 12) / 4 = 24.

Why is LCM important for fractions?

The LCM of two denominators gives you the least common denominator (LCD) needed to add or subtract fractions. Using the LCD keeps numbers small and makes simplification easier.

Can the LCM equal one of the numbers?

Yes. If one number divides the other evenly, the LCM is the larger number. For example, LCM(4, 12) = 12 because 12 is already a multiple of 4.

Related Calculators