Wood Cutting Calculator
The Blade Itself Eats Into Your Material
Every cut a saw makes removes a sliver of wood as sawdust — the kerf — and that width adds up across a series of cuts on a single board. Ignore it and a cut list that looks like it should fit comes up one piece short; account for it properly and you know exactly how many full pieces a board yields before you start cutting.
The Formula
Each cut piece effectively "consumes" its own length plus one kerf width, since the blade removes that much material between one piece and the next. Rounding down (floor) reflects that a partial piece at the end of the board isn't usable at the target length.
Worked Example
| Input | Value |
|---|---|
| Board length | 96 in |
| Piece length | 18 in |
| Kerf | 0.125 in |
| Pieces yielded | 5 |
| Leftover material | 5.5 in |
A standard table saw blade typically has a kerf around 0.125″; thin-kerf blades run closer to 0.09–0.1″, which yields slightly more usable material from the same board on long cut lists.
Where This Matters
- Planning a cut list before buying lumber — knowing exactly how many pieces a given board length yields tells you how many boards to buy for a project, rather than guessing and running short mid-build.
- Minimizing waste on repetitive cuts — when cutting many identical pieces (shelving, slats, moulding), even a small kerf miscalculation compounds into a meaningfully wrong material estimate.
- Comparing blade choices — switching to a thin-kerf blade on a project with many cuts can measurably reduce the number of boards needed, which this calculator makes visible.
How to Use This Calculator
- Enter the Board Length in inches.
- Enter the Cut Piece Length in inches.
- Enter the Blade Kerf Width in inches (optional, defaults to 0.125).
- Select Calculate to see the number of pieces and leftover material.
Related Calculations
Total up board feet for a full order with the Board Foot Calculator, or price out the lumber with the Lumber Cost Calculator.