Fraction calculator for measurements
Work in halves, eighths, or thirty-seconds. Keep the answer exact.
Add and subtract fractional inches or mixed numbers without converting them to decimals first. The calculator starts with inches selected.
Start calculatingTry a measurement
2 3/4 in + 1 5/8 in
= 4 3/8 in
Builder’s calculator
Editing first whole inches
Tap any field to edit · Backspace moves back when empty
Settings
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Follow your phone’s language, or choose one for Inch Plus.
If your preferred languages aren’t supported, Inch Plus uses English.
Your measurements and units stay the same when you change language.
Check your measurements and results before cutting or installing. Calculations run in your browser.
Enter the fraction as you see it.
For 2 3/4 inches, enter 2 in the Inches field, 3 above the fraction line, and 4 below it. The top number is the numerator; the bottom number is the denominator.
For a fraction smaller than one inch, such as 3/8, leave the whole-inch field blank or enter 0. For whole inches, leave both fraction fields blank. A fraction needs a denominator greater than zero.
Enter the second measurement and choose an operation. The answer updates as you type; Calculate saves it to this browser’s history.
Different denominators are fine.
In the example, 3/4 is the same as 6/8. Adding 6/8 and 5/8 gives 11/8, or 1 3/8. Add the whole inches, 2 + 1, and the total is 4 3/8 inches.
Subtraction works the same way: 3/4 in − 1/8 in = 5/8 in. Inch Plus simplifies the result automatically.
Multiply or divide by a number.
To double 2 3/4 inches, select multiply and set the second unit to Number (no unit), then enter 2. The result is 5 1/2 inches.
Multiplying two lengths produces an area. Dividing one length by another produces a ratio. To keep your result as a length, use a unitless multiplier or divisor. The equal-parts calculator sets this up for division.
Exact first. Rounded when needed.
The fraction answer is exact. Tape rounding can provide a nearby mark on your tape while keeping the exact answer visible. Use the feet and inches calculator when your measurements include feet.