Cut List Optimizer (Boards, Kerf and Waste)

Type the boards you can buy and the pieces you need, and this cut list optimizer works out how many boards to buy and which piece to cut from which board. It allows for the blade kerf on every cut and a squaring cut at each end of the stock, then draws the layout so you can take it to the saw. It is the one-dimensional case: boards, dowels, trim, pipe and anything else cut to length. For plywood and sheet goods use the plywood cut calculator.

Cut list optimizer calculator

How it works

The parts are sorted longest first. Each piece goes into the open board where it leaves the least room (best fit). When no open board has room, the optimizer opens a new board, trying each stock length you listed and keeping the one that ends up with the smallest share of waste after greedily filling it with the pieces still to be cut.

Usable length = stock length − 2 × end trim
Room left after a piece = room − piece length − kerf
Waste = (total stock − total part length) ÷ total stock, so it counts kerf, trim and offcuts

This is a heuristic, not an exhaustive search. For a hobby project of a few dozen pieces it usually matches or beats a hand layout, and it never places a piece where it will not fit.

Worked example

A small bench: four 30-1/2 in legs, four 22 in aprons, two 36 in stretchers and eight 14-1/4 in slats, cut from 8 ft or 10 ft boards with a 1/8 in kerf and 1/2 in trimmed from each end:

Units: Inches and feet
Stock lengths you can buy: 96; 120
Parts to cut: 4 x 30-1/2 legs; 4 x 22 aprons; 2 x 36 stretchers; 8 x 14-1/4 slats
Saw kerf: 0.125 in
Trim off each end of the stock: 0.5 in

The calculator gives:

Boards to buy: 5 boards: 1 x 120", 4 x 96"
Waste: 21.4% of the stock (108" of offcuts, kerf and trim)
Total stock: 504" (42 linear ft)
Parts: 18 pieces, 396" in total
Board 1 (120"): 30-1/2 legs, 22 aprons, 22 aprons, 22 aprons, 14-1/4 slats | offcut 7-5/8"
Board 2 (96"): 36 stretchers, 36 stretchers, 22 aprons | offcut 5/8"
Board 3 (96"): 30-1/2 legs, 30-1/2 legs, 30-1/2 legs | offcut 3-1/8"
Board 4 (96"): 14-1/4 slats, 14-1/4 slats, 14-1/4 slats, 14-1/4 slats, 14-1/4 slats, 14-1/4 slats | offcut 8-3/4"
Board 5 (96"): 14-1/4 slats | offcut 80-5/8"

The optimizer takes one 10 ft board (a leg, three aprons and a slat) and four 8 ft boards: the two stretchers share a board with an apron, three legs fill another, six slats a third, and the last board carries a single slat, so a shop offcut would do for that one. That is 42 linear feet of stock for 33 feet of parts, 21% waste, and every board is shown with its offcut so you can see where a shorter piece would fit.

Notes and limits

Enter parts at their final length. If you rough-cut long and trim later, add the extra to each part rather than to the kerf.
Kerf matters: twenty cuts with a 1/8 in blade eat 2-1/2 in of board.
Stock with a limited count (“3 x 96”) is used up first where it wins; a plain length is treated as unlimited.
Grain, defects and colour matching are yours to judge; the diagram shows lengths only. Move a piece by editing the list.
Lumber yards sell nominal lengths that are often an inch or two long. The trim allowance covers checked or dirty ends, not that extra.

Frequently asked questions

How do you make a cut list for woodworking?

List every part with its final length and quantity, sort the list longest first, and pack the pieces onto boards, remembering that each cut removes a blade width. This calculator does the packing and draws the result.

How much waste should I allow when buying lumber?

It depends on how well the parts fit the board lengths, which is exactly what the optimizer shows. Simple projects come out around 10 to 15% waste; awkward lengths can be 30% or more. Add more for defects and grain matching.

Does the saw kerf really matter in a cut list?

Yes. A 1/8 in kerf on eight cuts is an inch. If three 32 in pieces are planned from a 96 in board, the third one comes up short.

Can I use this for pipe, trim, dowels or metal?

Yes. Anything cut to length from stock works the same way. Set the kerf to your blade or cutter width, or 0 for a shear.

Why did it choose the longer board?

Because it left less waste after filling it. If the price per foot differs a lot between lengths, list only the ones you are happy to buy.

Sources

Last reviewed: 26 September 2026. The calculation is covered by automated tests with known answers taken from the sources above. Found an error? Please let us know.