Toolnido

Tape Measure Fraction Calculator: Add, Subtract and Cut in 1/16 Inch

Add and subtract feet, inches and fractions down to 1/64 in, plan cuts from stock boards with saw kerf, and convert decimals to the nearest tape mark. Runs in your browser.

What do you want to do?
Tape buttons: build a measurement

Or type straight into the list below. Examples: 5 3/16, 5-3/16, 2' 4 1/2", 2 ft 4.5 in, 3/4, 150 mm.

Lengths (one per line)

When to use this

  • You have a list of measurements such as 5 3/16 and 12 7/8 and want the exact total without converting to decimals.
  • You are cutting several pieces from 8 ft boards and want to know how many boards you need once the saw blade width is counted.
  • You have a decimal such as 0.6875 in from a plan or a caliper and want the nearest mark on a tape measure.

How to use

  1. Pick add and subtract, cut list, or convert, and choose the smallest mark you can read on your tape.
  2. Build a measurement with the feet, inches and fraction buttons, or type lines such as 5 3/16, 2' 4 1/2" or 150 mm.
  3. Start a line with - to subtract it, or write 3 @ 24 1/2 for three pieces of that length.
  4. Press Calculate and read the total in feet and inches, in inches only and in millimetres.
  5. Copy the result, download a CSV or print the page.

Examples

Understanding the result

Every length is converted to whole sixty-fourths of an inch, so adding and subtracting fractions gives an exact answer. The total is then rounded to the step you chose, 1/16 in by default, with a value exactly halfway rounded up. Decimal and metric entries cannot always land on a mark, so they are rounded to the nearest 1/64 in when read and the line is flagged. In the cut list the saw kerf is counted between neighbouring pieces on the same board.

Limitations

FAQ

How do I add fractions of an inch?

Give every fraction the same denominator, add the tops, then turn the result back into whole inches and a fraction. For example 3/16 + 7/8 = 3/16 + 14/16 = 17/16 = 1 1/16. The calculator does this for every line at once.

How do I convert a decimal to a tape measure fraction?

Multiply the decimal part by 16 and round to the nearest whole number, then write it over 16. For 0.6875 in that is 11/16. Use the convert option to do it for a list and see how far off each rounding is.

How many 1/16 marks are in an inch?

There are 16, so each mark is 0.0625 in or about 1.59 mm. Halves, quarters and eighths are every 8th, 4th and 2nd mark.

Why does the cut list use a kerf?

A saw blade turns some wood into dust. If you cut several pieces from one board, each cut between pieces removes the blade width, so the pieces together need slightly more than their lengths add up to.

Can I mix feet, inches and millimetres?

Yes. Each line is read on its own, so 2' 4 1/2" and 150 mm can sit in the same list. Metric values are rounded to the nearest 1/64 in.

Is my list saved anywhere?

No. Everything is calculated in your browser and nothing is sent to a server.

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