LCD Calculator

The Least Common Denominator (LCD) is the smallest number that all denominators divide into evenly. It is needed to add or subtract fractions and equals the Least Common Multiple (LCM) of the denominators

The calculator uses the standard published formula for lcd. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: LCD = LCM of all denominators. Each step in the calculation is shown so you can verify the result manually.