Boards to buy versus cut pieces
The shopping list counts store-length boards. The cut list counts the shorter parts cut from those boards. One board can supply several parts, so these totals are different. Sheet counts cover floor plywood, roof sheathing and siding; roof area is sloped surface area, not floor area.
A worked 10 × 12-foot example
Gable roof, 10-foot front, 12-foot depth, 6/12 pitch, treated skids on gravel, LP SmartSide siding, asphalt shingles, moderate snow setting, 6-inch overhang, front double door (62 × 80-inch rough opening), one 24 × 36-inch left window and walls framed 8' 1-1/8" tall from standard precut studs.
For this shed the plan comes to 203 cut pieces from 133 boards bought, 26 sheets, 164 sq ft of roof and $4,095 in required materials. Open this worked example in the calculator.
From this example’s cut list
| Stock label | Cut length | Pieces |
|---|---|---|
| PT 4x6 | PT 4x6 @ 144" | 3 |
| PT 2x6 | PT 2x6 @ 144" | 2 |
| PT 2x6 | PT 2x6 @ 117" | 10 |
| 2x10 | 2x10 @ 65" | 2 |
Stock sizes, saw loss and leftovers
A label such as 2x4 is a nominal stock name, not the exact dressed cross-section used in the drawings. Board feet here use nominal dimensions. The cut length describes how long a part is; the stock length describes the board you buy. The optimizer considers 8-, 10-, 12-, 14- and 16-foot stock, plus precut 2x4 studs.
It groups parts by stock, packs longer cuts first, allows 1/8-inch saw kerf between cuts and then shortens stock where the cuts still fit. It aims to cut waste and keep the bill down; it does not promise the perfect purchase. This example’s remaining offcuts are 5.4% of purchased board length. That percentage measures leftover length, not sawdust or a percentage added to the order.
This is not a blanket 10% waste allowance. Sheets are laid out the way they face on the wall or roof, and the small gaps between panels take up the saw cut, so no extra sheet allowance is added. Asphalt shingles already include 10% waste before rounding to bundles; gravel includes a 15% compaction allowance. Fasteners are rule-of-thumb quantities rounded to packages. Do not automatically add another 10% to every line; discuss damaged stock, mistakes and available lengths with your supplier.
What the free list includes
The free calculator gives lumber, floor/roof/siding sheets, foundation material, roofing, fasteners, connectors, door/window items and finishing with estimated prices. Optional items appear separately and are excluded from the required total. These are built-in 2025–26 US price assumptions, not live store quotes; estimates exclude labor, tools, permits, tax and delivery. Check your local quantities and prices.
The paid designer adds the complete cut list, a board-by-board cutting plan, sheet layouts, build steps, a 3D model and printable drawings. The sample above shows the difference before you buy anything.
Check local snow and wind loads, setbacks, foundation and permit rules with your building department or a qualified professional. A snow dropdown is not a site-specific structural design. See the same-footprint roof comparison or the size pages.