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Cut List Optimizer

What it's for

You have a list of parts to cut and one length of stock to cut them from. The optimizer works out which parts come out of which board, how many boards to buy, and how much ends up as offcut and sawdust. The parts can be typed in, or sent over from another calculator. Nothing here is checked against code.

Step by step

The screen opens with 8' 0" stock, a 1/8″ kerf and no cuts. There is no answer until you add one. The example is a job with three parts cut from 12' 0" stock.

Cut List Optimizer with a job entered: STOCK LENGTH 12' 0", KERF 1/8″ selected from None, 1/16″, 1/8″ and 3/16″, CUT 1 5' 6" × 8, CUT 2 2' 10-1/2" × 12, CUT 3 1' 10-1/4" × 10, with a trash button on each, then ADD CUT and the top of RESULTS (Board 1 to Board 4, each a bar under its parts). The answer bar under the title reads 9 boards, a green Every cut fits the stock and 10.1% waste incl. kerf — offcuts + sawdust; a kerf between parts, one more before an offcut. RESET sits beside the help button. 1 2 4 5 6
The inputs: stock, kerf, then one block per part. Step 6, ADD CUT, is at the end of the list. The answer is already in the bar under the title.
  1. STOCK LENGTH — the length of the boards you are buying. It opens at 8' 0". The example uses 12' 0". One run uses one stock length.
  2. KERF — the width your blade turns to sawdust: None, 1/16″, 1/8″ or 3/16″. It opens at 1/8″.
  3. Tap Add your first cut. A line headed CUT 1 appears.
  4. On that line, tap the length — the finished length of that part. CUT 1 in the example is 5' 6".
  5. Then tap the × count — how many of that part, 8 here — and type the number. There is no stepping through one at a time.
  6. Tap Add cut for each different length. The example adds 12 at 2' 10-1/2" and 10 at 1' 10-1/4". The bin at the end of a line deletes that part.
  7. Read the answer in RESULTS, under the cuts: 9 boards, then one row per board. The headline stays pinned under the title while you scroll.
  8. Scroll to the end of the board list for the waste line and the check.
  9. Under RESULTS are MATERIALS and the buttons for taking the plan with you.
The same job scrolled down. The answer bar keeps 9 boards and Every cut fits the stock. RESULTS shows boards 2 to 9, each with a bar under it: boards 2 to 4 read 5' 6" · 5' 6" → 11-3/4" offcut; boards 5 to 7 each hold four parts at 2' 10-1/2" with a 5-1/2" offcut; board 8 holds six parts at 1' 10-1/4" with a 9-3/4" offcut; board 9 holds four at 1' 10-1/4" with a 4' 6-1/2" offcut. Then come the waste line, the green Every cut fits the stock, the link Check before you cut · Measure twice, MATERIALS Stock boards — 12' each 9 pcs and the top of the CUT SHEET and SAVE buttons. 7
Step 7 is the answer, 9 boards, with a row and a bar for each board.
The end of the results: boards 5 to 9, board 9 with a 4' 6-1/2" offcut, then 10.1% waste incl. kerf — offcuts + sawdust; a kerf between parts, one more before an offcut, and Every cut fits the stock in green. MATERIALS reads Stock boards — 12' each, 9 pcs. Below are the buttons CUT SHEET and SAVE on the first line, CUT LIST and SEND LIST on the second. The answer bar under the title reads 9 boards. 8 9
Step 8: the waste line and the green check. Step 9: MATERIALS and the four buttons, lit because the job has cuts.

Parts sent from another calculator

Stairs and Hip & Valley have an OPTIMIZE button with their export buttons. It opens this screen with the parts already in the CUTS list, and sets STOCK LENGTH when the sending calculator suggests one. The incoming parts replace whatever rows were here. After that you can edit them like any others. The plan buys only the boards the parts need, and RESULTS says so: the sending screen's MATERIALS adds its waste spares, so it can list more — a 3-stringer stair buys 4 boards there (3 and a spare) and 3 here. See Send to the Cut List Optimizer.

Reading the results

Before there is a job the headline reads Add your first cut. If you have rows but none has both a length and a quantity, it reads Give a cut its length.

The headline is the number of boards to buy. In the example it is 9 boards. If it ends (placed cuts only), some parts did not fit and are not counted. Look at the red line.

The board list comes next, one row per board: the parts cut from it in order, then the offcut if there is one, with a bar under it showing the parts in gold and the offcut in grey. Cut each board in the order given. In the example, boards 1 to 4 each take two 5' 6" parts and leave an 11-3/4" offcut. Boards 5 to 7 each take four 2' 10-1/2" parts and leave 5-1/2". Board 9 is the last and part full, with a 4' 6-1/2" offcut.

The waste line is everything you buy that does not end up as a part — offcuts and kerf together — as a percentage of the stock bought. The example reads 10.1% waste incl. kerf, and the line says how the kerf is counted: a saw passes between pieces, so three parts from one board take two kerfs, one fewer than the parts on that board. The offcut, if there is one, takes the last cut.

The check. Green reads Every cut fits the stock. Red reads DOES NOT FIT STOCK: followed by the parts that are longer than the stock, such as a count and a length. Those parts are left out of the plan, never dropped quietly. The fix is a longer STOCK LENGTH, or correcting the LENGTH of that cut.

The optimizer tries the ways the parts can go on the boards until it has the fewest boards they can be cut from, however long the list. A short list is done as you type. A long one with many different lengths can take a moment longer: the board count shows at once and can drop a board or two a fraction of a second after you stop typing. If the search stops before it can prove a plan is the fewest, the results add a line such as Not proven the fewest — the search stopped first; no layout uses fewer than 18 boards, with the lowest count any layout could reach, so you can see how far off the plan might be. The cut sheet carries the same line.

This results card has no BASIS & WHAT WAS ASSUMED row and the screen has no drawing. The two things it assumes are on the screen: the stock length and the kerf.

MATERIALS is one row, the stock boards to buy, with the stock length after the dash. The example reads Stock boards — 12' each, 9 pcs.

The buttons wait for a job. CUT SHEET shares a PDF with the inputs, the board count, the waste and the parts for every board, on as many pages as the list needs. SAVE puts the result in History. CUT LIST puts the plan on the Lock Screen, one check-off per board with that board's cuts, for the first 30 boards. SEND LIST sends the same list to another phone as a checkable page.

Cut List Optimizer is a Pro calculator. The cut sheet, the cut list on the Lock Screen, sending a list and History are Pro too. Pro is a one-time purchase. See Free and Pro.

Common mistakes