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Tape measure calculator: feet, inches and fractions

Add and divide feet, inches and sixteenths.

Open the Tape Calculator tool

Free. Runs in your browser, no account, and keeps working offline.

What it does

Type measurements the way you read them off the tape — 4′ 3 1/2″, 48 3/8, 5/16 — and add, subtract, multiply or divide them. Answers come back in feet and inches with a fraction, to the nearest sixteenth, so you can go straight to the saw.

It replaces the scrap of drywall: take a stud length less a top plate, the width of a run less two reveals, or the length of a piece divided by three. Multiply and divide are worked before add and subtract, like any calculator.

The half key finds the center of any length, and Equal spaces splits a length into any number of equal parts and lists every mark.

Worked example

Typed the way it reads off the tape: feet with ′, inches with ″ (optional), fractions as 3/8.

48 3/8 − 2 × 3/4 ÷ 3
47 7/8″
4′ 3 1/2″ + 18 5/16″
5′ 9 13/16″
97 1/4″ split into 3 equal spaces: marks at
32 7/16″, 64 13/16″

× and ÷ are worked before + and −, the way a calculator does.

Try it with your numbers

Questions

How do I add feet and inches with fractions?

Type them as you'd say them: 4' 3 1/2" + 18 5/16. The calculator converts everything to inches, adds, and shows the answer in feet, inches and sixteenths.

How do I divide a length into equal parts?

Use Equal spaces: enter the length and the number of spaces, and it lists each mark from the left end. Two spaces is the center.

How precise are the answers?

Answers round to the nearest 1/16″, the finest mark most tapes show.

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