Cut list calculator
List the parts you need and the boards you have, and get a plan that cuts them from as few boards as it can find, with the saw kerf and end trim counted. It works for boards, 2x4s, moulding and anything else cut to length. Everything runs in your browser, offline once the page has loaded, and your list stays on your device.
Units
The blade’s width: printed on it, often 1/8 or 3/32 in.
Cut off one end of each board first, to square it.
Boards needed
3
3 × 96 in. 73% of the wood ends up in parts.
Why: 3 boards, the fewest possible for these parts.
Board 1 (96 in)
Cut 3 × 30 in leg; offcut 5 3/4 in.
Board 2 (96 in)
Cut 30 in leg, 2 × 22 1/2 in rail; offcut 20 3/4 in.
Board 3 (96 in)
Cut 2 × 22 1/2 in rail; offcut 50 7/8 in.
Why these numbers?
The situation
8 parts totalling 210 in, cut from 96 in boards with a 1/8 in kerf.
From your input: parts, boards, kerf and trim
What that means
Each part uses its length plus one saw kerf. A board can give back one kerf, because the last part needs no cut after it, so each board holds 96 1/8 in of that.
Arithmetic: exact by definition
So
By length alone: 211 in ÷ 96 1/8 in = 2.195, so no plan can use fewer than 3 boards.
Arithmetic: exact by definition
The number
The plan uses 3 boards, which meets that bound: the fewest boards possible.
Arithmetic: exact by definition
How the plan is made
Each part uses its length plus one saw kerf, the width of the cut the blade removes. The last part on a board needs no cut after it, so each board gets one kerf back. If you trim the end of each board square first, that comes off before any part.
The calculator fills one board at a time. Each board takes the longest part still to cut, and then the combination of other parts that fills the rest of it best. With several board lengths, it picks the length that leaves the smallest share of the board as offcut. This is a heuristic, not a search of every possible plan, so the page tells you exactly what it can prove: with one board length, it works out how many boards the parts need by length alone, and only calls a plan the fewest possible when it meets that number or a full search shows one board fewer can’t work.
Entering parts on a phone
Fill a row per size with how many you need, or open “Paste a list” and type one part per line, the way you’d write it on the back of a board: 4 @ 30 leg, 2 @ 22-1/2 rail. A count needs “@”, “pcs” or “ea”. Lengths take shop fractions in inches or decimals in millimetres. Your list is kept in the address, so you can share or bookmark a plan, and in this browser for next time.
The lumber sizes chart has the actual thickness and width of each nominal size. To total the board feet of what you buy, use the board foot calculator.