LCD Calculator (Least Common Denominator)

About Our LCD Calculator

Our free LCD Calculator makes it easy to find the least common denominator (LCD) for any list of fractions. Whether you're adding, subtracting, or comparing fractions, the LCD helps you rewrite them with a common denominator, making calculations simple and accurate. Just enter your fractions separated by commas, and get the LCD with a clear, step-by-step breakdown. This tool is ideal for students, teachers, and anyone who needs to work with fractions in math, science, or everyday life.

LCD Formula

To find the Least Common Denominator (LCD) of two or more fractions, use the Least Common Multiple (LCM) of their denominators.

List all denominators of the given fractions.
Find the Least Common Multiple (LCM) of these denominators.
The LCM is the LCD.

LCD(a/b, c/d, ...) = LCM(b, d, ...)

Examples

Example 1

Input: 1/2, 1/3

Output: 6

To find the LCD of 1/2 and 1/3: the denominators are 2 and 3. The least common multiple (LCM) of 2 and 3 is 6, so the LCD is 6.

Example 2

Input: 3/4, 5/6, 7/8

Output: 24

For 3/4, 5/6, and 7/8: the denominators are 4, 6, and 8. The LCM of 4, 6, and 8 is 24, so the LCD is 24.

Frequently Asked Questions

What is LCD?

LCD stands for Least Common Denominator. It's the smallest number that all denominators of a set of fractions can divide into evenly.

How do you find the LCD?

To find the LCD, list the denominators of all fractions, then find their least common multiple (LCM). The LCM is the LCD. This calculator automates the process for you.

Why is finding the LCD important?

Finding the LCD is essential when adding, subtracting, or comparing fractions. It allows you to rewrite fractions with a common denominator, making calculations easier and more accurate.

Can I use this calculator for more than two fractions?

Yes! You can enter as many fractions as you like, separated by commas. The calculator will find the LCD for all of them.