BuildMeasureHow to Measure Saw Kerf
Kerf is the width of the slot left by a cutting tool. Every through-cut removes that width from the stock. Ignoring kerf can turn a cut list that appears to fit into one that runs short near the final piece.
Use a test cut
Use the blade, machine, feed setup, and material planned for the project. Make one complete cut through a straight scrap. Bring the two offcuts together and measure the missing width, or measure the slot directly with a suitable tool. Repeat the test if the result is difficult to read.
Why the printed blade width is only a starting point
The plate thickness, tooth set, runout, wear, and machine setup can affect the real cut. A blade marketed with a particular kerf may leave a slightly different slot in practice. Measuring the setup gives the cut planner a value connected to your shop.
Count cuts carefully
The number of cuts is not always one less than the number of pieces. Cutting four pieces from one board often requires four crosscuts because the last piece must still be separated from the remaining stock. Your workflow can differ if an existing end is already suitable or if you trim both ends first.
Add end trimming separately
Kerf does not include cracks, checking, a rough factory end, or the material removed to square a board. Reserve those allowances before fitting pieces into the usable length. Label the numbers in your notes so you know which allowance covers each loss.