What is saw kerf?
Kerf is the width of material a saw blade removes with every cut — typically 3–4 mm on a panel saw, more on a coarse blade. It sounds tiny, but it is consumed on every cut line. Across a sheet packed with twenty parts, an ignored 4 mm kerf can throw your last row off by several centimetres, leaving a finished piece short. This calculator adds the kerf between every part so the layout reflects what the saw will actually do.
Why kerf decides waste
Two identical part lists can need a different number of sheets purely because of kerf. A tighter blade (thin-kerf) recovers usable width; a thick blade eats it. Enter your real kerf below, optimize, and watch the efficiency percentage move — it is the cheapest way to see whether a thinner blade pays for itself on a big job.
For saving cut lists and cutting on the shop floor, the free CutList app applies the same kerf logic offline on your phone.