Locate the inches side of the tape (often marked with larger numbers) and/or the centimeters side (often marked with “cm”).
Identify the zero mark on the tape (the end hook or “0” line).
Place the hook firmly against one end of what you are measuring (for outside measurements) or align the tape edge with the inside corner (for inside measurements).
Keep the tape straight and taut without bending or sagging.
Read the measurement at the exact point where the other end meets the tape.
For inches: use the longest lines for whole inches; the next shorter lines for 1/2; then 1/4; then 1/8; then 1/16 (depending on the tape).
For mixed numbers: record the whole inches and then the fraction indicated by the corresponding line (e.g., 5 3/4).
For centimeters: read the number at the longest line; smaller lines between numbers represent millimeters (1 cm = 10 mm).
If the tape shows both metric and imperial, confirm you’re using the correct unit side before recording.
If the edge falls between marks, estimate to the nearest smallest division shown on the tape.