How to read a tape measure

The marks, longest to shortest

The longest lines with numbers are whole inches. The next longest, halfway between, is the half inch. Then come quarters, eighths, and on most tapes sixteenths, which are the shortest lines. Some tapes also show thirty-seconds on the first foot.

Reading a measurement

Find the last whole-inch number before your edge. Count the small marks past it, and put that count over the number of marks in one inch. If the edge is 6 marks past the 5-inch line on a tape with sixteenths, that's 5 6/16", which reduces to 5 3/8". To reduce a fraction, halve the top and bottom until you can't anymore.

The marks that aren't fractions

Many tapes highlight every 16 inches, the usual spacing of wall studs, and mark every 19.2 inches with a diamond or black box for truss layout. These are framing shortcuts, and you can ignore them for most woodworking.

The sliding hook

The metal hook on the end moves a little on purpose. It slides in by its own thickness when you push it against a surface and out by that amount when you hook an edge, so the reading is right either way.

When the answer falls between marks

Round to the closest mark you can see. The tape measure calculator does the math and rounds for you, the fraction converter switches to decimals or millimeters, and the fraction chart is a quick lookup.