How this calc works

Your tape measure reads in fractions; most calculators answer in decimals. This calc closes that gap: give it a decimal inch and it returns the nearest fraction in tape-measure increments — sixteenths by default, the marks actually printed on the blade. A result of 7.1875 comes back as 7-3/16, the number you can actually cut to.

It works by finding the closest fraction with a denominator your tape uses, then reducing it — 6/16 becomes 3/8, 8/16 becomes 1/2 — so you read the same simplified fraction the marks show. This is the everyday conversion behind every other calc on the site that returns a measurement.

Common mistakes

The error people make doing it by hand is rounding to the wrong precision — forcing everything to the nearest eighth when the cut needs a sixteenth, or carrying false precision the tape cannot show. Match the fraction to the marks on your blade.

The second is letting decimal rounding compound. Round 7.1875 to 7.19 to 7-3/16 and you may be fine on one cut, but stacked across a long layout the small errors add up to a visible gap. Convert once, from the full decimal.

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