Cut List Calculator
Three millimetres a cut costs a whole board.
Three millimetres a cut costs a whole board. Packs your piece lengths onto stock boards longest-first, with the saw kerf counted on every cut.
Comma separated, in millimetres. Repeat a length for each piece you need.
Boards needed
3
66% yield · 18 mm lost to the saw
The kerf is why a 2400 mm board does not yield eight 300 mm pieces. Three millimetres a cut sounds like nothing and costs a whole piece by the eighth — seven fit, the eighth does not, and a second board gets opened for it. Cutting longest first is what makes the packing work. Long pieces need whole boards; short ones can live in the offcuts long pieces leave behind, and reversing the order strands usable material. First-fit-decreasing is a heuristic, not an optimum. It is provably within about 22% of the best possible arrangement and usually much closer, which is more than good enough for a workshop and far faster than searching every arrangement.
How the Cut List Calculator works
Packs your piece lengths onto stock boards longest-first, with the saw kerf counted on every cut. Reports the layout board by board, the offcut left on each and the yield.
Also known as: how many boards do i need · cutting list optimiser · linear cut layout with kerf · how much timber for this project
Where to go next
The Cut List question rarely arrives on its own. These are the ones that usually come with it:
- Mitre Angle Calculator — Compound cuts move both angles at once.
- Percentage Calculator — Every common percentage question in one place.
- Age Calculator — Exact age in years, months, days, and total units.
- Z-Score Calculator — Standard deviations from the mean, and the percentile that follows.
Frequently asked questions
What is a kerf?
The width of material the blade turns into sawdust — typically 3 mm on a mitre saw and 3 to 4 mm on a table saw. It comes off the board with every single cut.
Why can't I get eight 300 mm pieces from a 2400 mm board?
Because seven cuts of 3 mm consume 21 mm. Seven pieces fit with room to spare; the eighth is 21 mm short, and a second board gets opened for it.
Why cut the longest pieces first?
Long pieces need whole boards; short ones can live in the offcuts long pieces leave behind. Cutting short first strands material that nothing else can use.
Is this the optimal layout?
Not guaranteed. It is a first-fit-decreasing heuristic, provably within about 22% of optimal and usually far closer. Searching every arrangement is impractical and rarely worth the difference.
Should I add extra for defects?
Yes. Real boards have splits, knots and snipe at the ends. Most workshops add 10 to 15% on top of a calculated list, or buy one extra board.
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