Saw Kerf Explained: Why Every Cut Steals 1/8 Inch

Kerf is the width of material a saw blade removes on each pass. It seems small until you cut a full sheet of plywood into strips and discover you're missing half an inch. Here's exactly what's happening and how to plan for it.

What kerf actually is

A saw blade is thicker than the material of the blade body — the teeth are splayed left and right so the body doesn't bind in the cut. The total width of the material removed by the tooth path is the kerf. A standard 10" table saw blade runs about 0.125" (1/8"). A thin-kerf blade runs about 0.094" (3/32").

Typical kerf widths

Full-kerf 10" table saw blade: 0.125" (1/8")
Thin-kerf 10" table saw blade: 0.094" (3/32")
Track saw / circular saw: 0.083"–0.098"
Miter saw: 0.100"–0.125"
Band saw: 0.025"–0.035"
Japanese pull saw: 0.012"–0.020"

How kerf compounds

Imagine you rip a 48" sheet of plywood into four 12" strips. That's three cuts. With a full-kerf blade at 0.125":

3 cuts × 0.125" = 0.375" total removed

Your four "12-inch" strips are actually 12.000", 11.875", 11.750", and 11.625" — unless you cut each one to width against a fence, resetting between strips. Every cut you make on the last strip steals from that strip alone.

The rule that saves you

Cut to a fence, not from a mark, whenever you need repeat widths. Setting the fence at 12" and ripping four times gives you four strips that are each 12" wide. The kerf is absorbed by the offcut side, not the workpiece side.

When you can't cut to a fence — long panels, angled cuts — you have to plan the kerf into your cut list. That's what a kerf calculator does: it tells you how much material you'll lose across N cuts so you can start with an oversized blank.

Kerf in a cabinet cut list

For assembled parts (shelves, sides, backs), kerf doesn't change the finished dimension — it only affects how much raw stock you need. A cabinet cut list calculator uses kerf to estimate sheet count and board feet, not to change part sizes. See the cabinet cut list guide for how those numbers connect.

How to reduce kerf loss

Use a thin-kerf blade on sheet goods — you get back ~25% of the material lost per cut.
Rough-break sheets with a track saw, then finish on the table saw for accuracy.
Layout the biggest parts first; small offcuts absorb kerf without hurting you.
Use a zero-clearance insert. Tearout that has to be re-jointed off wastes far more than kerf.

Want to see kerf loss live? Try the kerf calculator — enter your blade and cut count, get total material lost in inches and mm.