How to use this calculator
- Enter Run length in ft.
- Enter Spacing in in.
- Enter Extras allowance in %.
- Press Calculate. The highlighted row is your order quantity; the note beneath it translates the number into real-world terms.
Formula & constants
Members on layout = (run length in inches ÷ spacing) + 1. A 20 ft wall framed 16 in OC needs 16 studs before openings, corners and backers — which typically add 20–30%. Every default in the fields above is editable — when your supplier’s spec sheet lists a different density, coverage rate or price, enter that number instead. The waste and compaction allowances follow common trade practice; see our methodology page for the derivation of each formula and the standards it references.
Where this fits in the project
Framing quantities chain together: footings support posts, joists set the deck frame, and surface boards follow. Price hardwood and specialty stock in board feet, sheet goods by the sheet.
How this connects to your project
No quantity stands alone — each material in the chain depends on the ones around it. These are the planning steps that pair with the lumber calculator:
- Board Foot Calculator — Hardwood lumber is priced by board foot.
- Stud Calculator — Wall studs are dimensional lumber.
- Plywood Calculator — Lumber vs sheet goods for construction.
- Joist Calculator — Floor and ceiling joists are lumber members.
- Deck Calculator — Decks are framed with dimensional lumber.
- Stair Calculator — Stair stringers are cut from lumber.
- Roof Truss Calculator — Trusses are built from lumber members.
Frequently asked questions
Why order more than the layout count?
Corners take 2–3 studs each, openings need kings, jacks and cripples, and plates consume separate stock.
Is 24 in OC framing acceptable?
Yes for many walls per code with proper sheathing — it saves lumber but check drywall thickness and load requirements.
Last verified: — prices reflect current national averages. See our methodology.
Estimates are for planning. Material densities, coverage rates and prices vary by region and supplier — confirm final quantities before ordering, and check local code where structural or electrical work is involved.