13/16 inch is the short mark on a standard tape measure. It appears as a grey tick between each eighth-inch mark. The decimal equivalent is 0.8125 inches (20.64 mm).
On the Tape Measure
Count 13 marks of this size from the last full inch line to reach 13/16. On professional colour-coded tapes the grey marks are the shorter marks between the inch lines.
Conversion Reference
| Fraction | Decimal | Millimetres |
|---|---|---|
| 13/16″ | 0.8125″ | 20.64 mm |
| Half of 13/16 | 0.40625″ | 10.32 mm |
Common Woodworking Uses
Cabinet fitting, fine trim work, door hinge mortise depth. The 13/16 mark is common in: standard framing, finish carpentry trim fitting, and cabinet construction tolerances.
Also works for recipe halving — the fraction math is the same. Half of 13/16 cup is 13/32 cup. Use the TapeMath calculator for any fraction arithmetic.
How to find it fast: On the TapeMath visual tape, hover over any mark to see its fraction, decimal, and mm immediately — no counting required.