MOACUTSheet planning guide
How to Calculate Required Sheet Quantity
A sheet-area division gives a useful lower bound, but it does not prove that every rectangular part will physically fit. This guide shows how part dimensions, quantity, kerf, edge margin, and rotation turn an area estimate into a usable nesting result.
Last updated: October 1, 2026What required sheet quantity means
Required sheet quantity is the number of stock sheets allocated by a valid layout for the complete cut list. A cut list is not complete unless every part size is paired with its required quantity. Ten parts at 600 × 400 mm require ten separate rectangles in the layout, even when they share one line in the input table.
MOACUT expands each quantity into individual rectangular parts, sorts the parts from larger area to smaller area, and tries candidate positions from the bottom-left of sheets already opened. When a part cannot be placed on an existing sheet, the calculation opens another sheet. The displayed Required Sheets value is the resulting number of allocated sheets.
Start with the area lower bound—not the final order quantity
Area lower bound = ceiling(part area total ÷ one sheet area)
This calculation answers a narrow question: how many sheets would be needed if the part area could fill sheets without geometric constraints. It ignores whether widths can share a row, whether heights fit the remaining strip, and whether space must be reserved between parts or around the edge.
Use the area lower bound as a quick reasonableness check. Then run a nesting calculation to determine whether real rectangles fit. A result can legitimately use more sheets than the lower bound because an unused strip may have enough area but the wrong shape.
Inputs that can change the required sheet count
| Input | How MOACUT uses it | Planning consequence |
|---|---|---|
| Sheet width and height | Define the full stock rectangle. | Changing either dimension changes which rows and columns can fit. |
| Part width, height, quantity | Create the rectangles that must all be placed. | Two lists with equal total area can require different layouts. |
| Kerf | Acts as the required spacing between neighboring rectangles. | Spacing can prevent a row from fitting even when its part widths alone fit. |
| Edge margin | Reduces usable width and height by twice the entered margin. | A 10 mm margin reserves 10 mm on all four sides. |
| Allow rotation | Lets a non-square rectangle swap width and height by 90° during placement. | Rotation may fill a narrow remainder; turn it off for directional material. |
MOACUT workflow: input, calculate, inspect
- Enter the actual stock sheet width and height in millimetres, or select a preset and verify it against the material being purchased.
- Enter every rectangular part's finished width, height, and quantity. CSV import accepts rows in Width, Height, Quantity order.
- Set the inter-part kerf/spacing and the four-sided sheet edge margin for the planned process.
- Enable rotation only when turning a part by 90° is acceptable for grain, print direction, or surface finish.
- Sign in and run the nesting calculation. Inspect each sheet drawing, not only the summary cards.
- Read Required Sheets, Used Area, Material Utilization, Scrap, and Estimated Material Cost together.
MOACUT multiplies the calculated sheet count by the user-entered cost per sheet. It does not add machine time, labour, tooling, tax, delivery, or finishing costs.
Worked example: one sheet by area, two sheets in practice
This drawer-box cut list was run through MOACUT's current calculation path: quantity expansion, largest-area-first ordering, bottom-left candidate search, margin handling, rotation checks, and spacing-aware overlap rules. It stays within the free account limit (4 part types, 22 pieces), so you can reproduce it in the calculator.
Settings → kerf 3 mm; edge margin 10 mm.
The pure part area is (560 × 720 × 2) + (470 × 400 × 4) + (500 × 150 × 8) + (420 × 150 × 8) = 2,662,400 mm² (2.662 m²). One 1220 × 2440 mm sheet is 2,976,800 mm², so the area lower bound is one sheet. After the 10 mm margin, though, the parts would have to cover 91.7% of the 1200 × 2420 mm usable area with no wasted strips at all.
| Stock sheet and rotation rule | Area lower bound | MOACUT result | Parts per sheet | Overall utilization |
|---|---|---|---|---|
| 1220 × 2440 mm, rotation off | 1 | 2 sheets | 16 + 6 | 44.7% |
| 1220 × 2440 mm, rotation on | 1 | 2 sheets | 18 + 4 | 44.7% |
| 914 × 1829 mm, rotation off | 2 | 3 sheets | 4 + 13 + 5 | 53.1% |
| 914 × 1829 mm, rotation on | 2 | 2 sheets | 10 + 12 | 79.6% |
| 1500 × 3000 mm, rotation off | 1 | 1 sheet | 22 | 59.2% |
Why the 1220 × 2440 mm sheet needs a second sheet
Every part in this list is between 420 and 560 mm wide, so with rotation off only two fit side by side in the 1200 mm usable width. Each pair leaves a strip at the right edge: 1200 − (560 + 3 + 560) = 77 mm beside the 560 mm parts, 257 mm beside the 470 mm parts, 197 mm beside the 500 mm parts, and 357 mm beside the 420 mm parts. No part is narrower than 420 mm, so those strips stay empty even though together they hold a large share of the sheet. Sheet 1 takes 16 parts, and the last six 420 × 150 mm sides open sheet 2, which is only 12.7% occupied.
Allowing rotation lets some 150 mm-wide rotated sides use those strips, so sheet 1 takes 18 parts, but four still spill onto sheet 2. The sheet count does not change, which is why overall utilization stays at 44.7%.
Drawn from the same placement order the calculator uses: original orientation, rotated 90°, dashed line: 10 mm edge margin. Percentages are per-sheet utilization.
What the comparison means for purchasing
Two 914 × 1829 mm sheets (3.34 m² of stock) hold the whole list at 79.6% utilization when rotation is acceptable, while two 1220 × 2440 mm sheets (5.95 m²) run at 44.7%. A single 1500 × 3000 mm sheet also holds all 22 parts. Which option is cheaper depends on your supplier's price per sheet: run the list once per stock size, enter each price in Sheet Cost, and compare the Estimated Material Cost card.
The rotation rule and the stock size have to be decided together. If the drawer parts must keep their grain direction, the 914 × 1829 mm run needs three sheets instead of two. These are results of MOACUT's heuristic layout, not a proof that no better arrangement exists; the point is that area alone cannot answer the question, and the per-sheet drawings show where the space is lost.
How to read the result cards
- Required Sheets: number of sheet arrays created by the placement calculation.
- Used Area: sum of placed rectangle width × height, converted to square metres for display.
- Material Utilization: pure placed part area divided by full nominal area of all required sheets.
- Scrap: 100% minus overall material utilization. It includes all unoccupied area, including margin, spacing, and unusable remnants.
- Estimated Material Cost: required sheets × entered unit cost.
Each individual sheet drawing also shows its own utilization and scrap. This makes a lightly occupied final sheet visible even when the overall percentage looks acceptable.
Practical considerations and limits
MOACUT currently nests rectangular parts with optional 90° rotation using a bottom-left placement procedure. It is a practical estimate and layout, not a mathematical guarantee that no alternative arrangement could use fewer sheets. Re-run the plan when a sheet size, part quantity, spacing, margin, or rotation rule changes.
Do not use a layout as the sole instruction for physical cutting. Confirm actual stock dimensions, damaged edges, grain or print direction, machine holding areas, tool behaviour, tolerances, and process safety before ordering or machining.