Feet and Inches Calculator

How to use

1. 1Type a measurement on each row, for example 5' 3 1/2", 12 1/4", or 3.5 ft. Use the plus and minus buttons to add or subtract each one.
2. 2Pick what a bare number means (inches or feet) and the fraction to round the result to, such as 1/16 inch or Exact.
3. 3Read the total in feet and inches, exact inches, decimal inches, decimal feet, and metric, and copy any line you need.
4. 4To split or repeat a length, use the multiply and divide panel: enter the measurement, choose times or divide, and enter a plain number.
5. 5Add or remove rows as your list changes. Any value the tool cannot read is flagged on its row so the total stays correct.

About this tool

Feet and Inches Calculator does the measurement arithmetic that comes up constantly on a job site, in a workshop, and in a math class, and it does it without the rounding errors a normal calculator introduces. You enter measurements the way they are written or spoken, for example 5' 3 1/2", 12 1/4", 3.5 ft, or 7/2 inches, and the tool adds and subtracts a whole list of them, then reports the total four ways at once: as a clean feet-and-inches reading with a fraction, as exact inches, as a decimal value in both inches and feet, and as metric millimeters, centimeters, and meters. The reason the result can be trusted is that every value is held internally as an exact fraction of an inch rather than a decimal approximation, so a running total of thirds, eighths, or sixteenths never drifts to something like 7.31249 inches. Only the final feet-and-inches display is rounded, and you choose the fraction it rounds to, from one half down to one sixty-fourth, or you can keep the exact value with no rounding at all, which is why a sum that lands on 7 5/16" reads as 7 5/16" instead of an ugly decimal. The separate multiply and divide panel handles the other half of real measuring work: splitting a length into equal pieces (divide a board by the number of cuts), repeating a length (multiply by a count), or taking a fraction of a span (multiply by 0.5 for the center). Scaling a length by a plain number keeps the answer a length, which is the behavior people expect; the tool intentionally does not multiply one length by another, because that produces an area rather than a measurement. A forgiving parser accepts foot and inch marks, the words feet and inches, prime and double-prime symbols, mixed numbers, improper fractions, and decimals, so you can paste a dimension straight off a cut list or a plan and it just works, and any value it cannot read is flagged on its own row instead of silently corrupting the total. Everything is computed in your browser, so the measurements you type are never uploaded. Use it for framing and stud layout, trim and molding, cabinetry and shelving, fencing and decking, sewing and upholstery, model building, homework on imperial units, and any time you need to add a column of feet-and-inches measurements and get an answer you can mark on a tape. When you need to turn the result into other units the length converter takes over, the fraction calculator handles bare fractions without units, and the board foot and square footage calculators cover lumber volume and floor area.

Free to use. Works in your browser. No signup, no login.