PlywiseWhat is saw blade kerf, and how do you account for it?
Kerf is the slot a saw blade cuts: the material that turns into sawdust. Every cut you make costs one kerf, so a cut list that ignores it comes up short.
Updated 2026-10-29
Typical kerf widths
Kerf depends on the blade, not the saw. As a rough guide, a standard full-kerf table saw blade removes about 1/8" (3.2 mm), and a thin-kerf blade about 3/32" (2.4 mm). Track saw and circular saw blades vary widely. Blade wobble and tooth set make the real cut a little wider than the number on the package.
How to measure your kerf
- Cut partway into a piece of scrap.
- Measure the slot with calipers, or slip feeler gauges or drill bits into it until one fits snugly.
- Round up slightly. A plan that allows a hair too much kerf still works; one that allows too little leaves the last part short.
Why kerf matters on a full sheet
Kerf adds up fast when you cut many parts across a sheet. Ripping a 48" sheet into 3 1/2" strips with a 1/8" blade gives 12 strips, not the 13 that 48 / 3.5 suggests, because 12 strips plus 12 kerfs already take 43 1/2". The French cleat example shows exactly this.
Setting kerf in a cut list optimizer
In Plywise, the kerf is a project setting. The optimizer leaves one kerf between neighbouring parts and draws it on the cutting diagram, so the plan matches what your saw actually produces. If you also trim factory edges, set an edge trim as well; many sheets have chipped or out-of-square edges.