Measurement calculator
Feet and Inches Calculator
Add, subtract, multiply or divide measurements containing feet, inches and fractions.
Why this calculator exists
Feet and inches do not use the same base. Twelve inches make a foot, so normal decimal arithmetic creates mistakes when measurements are written as though 8 feet 6 inches were 8.6 feet.
Common mistakes
- Treating inches as base ten.
- Forgetting to borrow 12 inches when subtracting.
- Rounding each measurement before adding them.
Before you use the result
This calculator performs the math using the information you enter. Check the measurements and make sure the result fits the actual project before cutting, drilling, buying materials, or putting anything into service.