Plywood / Timber Calculator

Wood confuses budgets twice: once when you count sheets instead of square footage, and again when the lumber yard quotes board feet while your drawing thinks in studs. A floor is never "22 sheets" until you divide the floor area by the sheet, a wall is a stud count plus plates plus the clever extras at corners and openings, and neither matches the price until you multiply by a real cost per piece.

Plywood Calculator does both jobs in one tool: sheet counting for floors, roofs, walls and subfloor — including diagonal sheathing waste — and framing counts for walls, studs, joists and rafters with member length and plate extras. It reports sheets, linear feet, board feet and pieces with a live cost footing in either feet or metric sizes.

The learning guide explains the famous board-foot unit, which plywood thickness carries which load, and how corner and opening studs quietly double your stud count. Everything computes locally in your browser.

• Sheeting mode: Enter any rectangle (floor, roof, wall, deck) and get sheets, with 4×8, 4×10, 1200×2400 and other standard sheet presets.
• Framing mode: Wall or deck/roof members with length, spacing and stud/joist sizes, counting studs, joists, plates and rafters in pieces and linear feet.
• Board-feet conversion: See every piece in board feet, the unit hardwood and timber are actually sold in.
• Plate & extra counts: Explicit fields for top/bottom plates (as multiples of length) and extra corner/opening studs.
• Waste adjustment: 10 percent default for rectangular sheeting, up to 20 percent for diagonals and opening-rich walls.
• Cost:sheets and members: Price per sheet and price per piece sum into a whole material budget with no shipping arithmetic.
• Imperial or metric: Feet/inches or metres, with sheet sizes and member stock sized accordingly.
• Live estimate: Sheet counts, linear feet, board feet and cost all update as you type.
• Export: Copy or download the full lumber report as text, CSV or JSON.
• Learning guide: Board-foot explainer, plywood thickness guide, framing best-practice and lumber tips.

1. Pick the mode. Sheeting for surfaces (floors, roofs, walls, decks) or Framing for studs, joists and rafters.
2. In sheeting mode: Enter length and width, choose the sheet size, set the waste allowance, and read the sheet count plus board feet.
3. In framing mode: Enter the length to frame and the spacing (16 in / 400 mm, 24 in / 600 mm, or custom).
4. Choose the member. Wall studs, floor joists, rafters or a custom member with its own size in 2×4, 2×6, 2×8, 2×10, 4×4 or metric timber.
5. Add plates and extras. Toggle plates as multiples of framing length and add studs for corners and openings.
6. Enter cost. Price per sheet or per piece to see the material budget live.
7. Read the estimate. Counts, linear feet and board feet appear instantly.
8. Review the working. The maths shows spacing division, added end stud, plates and waste.
9. Export the report. Copy or download as text, CSV or JSON.
10. Check the guide. The learning tab explains board feet and sheathing thickness.

Example 1 — Floor sheathing. A 24×12 ft floor at 4×8 sheets: 288 sq ft ÷ 32 = 9 sheets + 10% waste ≈ 10 sheets of 3/4-inch plywood.

Example 2 — Wall studs. A 16 ft wall of 2×4 studs at 16-inch spacing: (16×12)÷16 + 1 = 13 studs, plus 2 plates (2×16 ft) and 2 corner + 2 opening studs ≈ 17 studs and 32 plate feet.

Example 3 — Deck joists. A 10 ft deep, 16 ft wide deck at 16-inch spacing: (16×12)÷16 + 1 = 13 joists of 10 ft, plus 2 rim joists = 15 pieces ≈ 150 linear ft.

Example 4 — Board feet on hardwood. 20 planks of 1×6×8 ft oak: each is 1×6×8 ÷ 144 = 3.33 BF → 66.7 BF total, priced per BF.

Example 5 — Roof sheathing. A 20×30 ft roof plane (600 sq ft) with diagonal sheathing: 600 ÷ 32 × 1.15 ≈ 22 sheets, the extra 15 percent covering the diagonal waste.

• Sheets and studs in one tool: Stop juggling two calculators for the floor deck and its joists.
• Buy the unit you are quoted: Board feet always shown alongside sheets and pieces — no conversion guess at the yard.
• No more corner/opening shock: The extra-stud field keeps the framing count honest without you re-deriving layout math.
• Waste that matches the job: Diagonal and opening-rich sheathing gets the 15–20 percent it really needs.
• Cost without a spreadsheet: Live per-sheet and per-piece summing answers "what will this cost?" before you commit.
• Explainable numbers: Every count follows from spacing, length, plates and waste in the working line.
• Export-ready: Text, CSV and JSON reports drop into the purchase order.
• Free and private: No uploads, no accounts, no logging.