Enter the first measurement using the fraction keypad (e.g. 3 5/8), tap +, enter the second measurement (e.g. 1 11/16), and tap =. TapeMath shows the result — 5 5/16″ — on the visual tape canvas instantly. The ″ key separates the whole number from the fraction.

Kerf is the width of material removed by a saw blade during each cut. A standard table saw blade removes 1/8 inch. A thin-kerf blade removes 3/32 inch. A Japanese pull saw removes about 1/32 inch. If you cut 5 pieces from one board without accounting for kerf, you lose nearly 1/2 inch of material. The TapeMath cut list builder subtracts kerf automatically.

Tape measure marks from tallest to shortest: whole inch (red, longest), 1/2 inch (blue, second tallest), 1/4 and 3/4 (green), 1/8 marks (dark, medium height), 1/16 marks (lightest, shortest). Hover over any mark on the TapeMath tape to see its exact fraction, decimal, and mm equivalent.

Enter any measurement and tap the half it button. TapeMath halves any fraction correctly: half of 3 5/8″ = 1 13/16″, half of 11 1/4″ = 5 5/8″. This is the most-used feature for woodworkers finding center points.