Lowest Common Denominator Calculator

This tool will calculate the Lowest Common Denominator (LCD) of any number of fractions. Simply set the value of each fraction, and then click 'Get LCD'.



The lowest common denominator or least common denominator (abbreviated LCD) is the lowest common multiple of the denominators of a set of fractions. It simplifies adding, subtracting, and comparing fractions. It is usually easiest to add, subtract, or compare fractions when each is expressed with the same denominator, called a "common denominator". For example, the numerators of fractions with common denominators can simply be added. Any common denominator will do, but usually the lowest common denominator is desirable because it makes the rest of the calculation as simple as possible.