Cut list calculator

Panels are a two-dimensional packing problem: rectangles placed on a rectangle. Lumber, trim, pipe, tube and bar are one-dimensional: lengths packed onto sticks. The maths is genuinely different, and running one through the other produces nonsense rather than a slightly worse answer.

Most jobs need both. Do them separately, then combine the two PDFs into one job pack and put the material totals for both on the front page, because that is the sheet purchasing works from.

Four inputs. The order matters because each one changes what the next is worth doing.

The calculator runs in the browser with no account: 20 part rows per session, CSV or XLSX import up to 5 rows, and 3 PDF exports a day with unlimited editing and re-running in between. Saved projects, stock inventory and DXF export need a paid plan.

Dividing total part area by sheet area gives a floor, never an answer. Parts have to tile in whole rows and columns, and every cut destroys material.

Along any edge, the number of parts that fit is the largest n satisfying n × part + (n − 1) × kerf ≤ stock dimension. That is the whole calculation, applied twice on a sheet and once on a stick.

The consequence worth internalising: kerf costs nothing when part sizes leave slack, and costs an entire row when they divide the stock almost exactly. A 2440 mm bar cut into 405 mm pieces looks like six (2440 ÷ 405 = 6.02) and yields five, because six needs 6 × 405 + 5 × 3.2 = 2446 mm.

Every calculator below is the same engine with stock sizes, kerf defaults and worked examples already set for that material. If your job is one of these, starting there saves entering things you would otherwise look up.

A 2100 mm run of workshop shelving: six shelves at 1000 × 400 mm in 18 mm plywood, two uprights at 2100 × 400, and a softwood frame from 2×4 - four legs at 2100 mm and eight rails at 940 mm.

Sheet side: eight parts, all 400 mm deep, on a 2440 × 1220 sheet. Ripped into 400 mm strips with a 3.2 mm kerf, the sheet gives three strips across the width (3 × 400 + 2 × 3.2 = 1206.4 mm, which fits; four would need 1609.6 mm and does not). Two uprights at 2100 mm take a strip each, and the six 1000 mm shelves need two more strips - so this job wants two sheets, not one, and the calculator tells you that before the delivery arrives rather than after.

Linear side: twelve pieces from 2×4. Four at 2100 and eight at 940 against 4.8 m stock is a different packing question entirely, and it belongs in the linear calculator.