Easy Wood Calc

How many sheets of plywood or OSB for a 24 ft wall, 8 ft high?

Short answer

A 24 × 8 ft wall (192 square feet) needs 7 sheets of 4 × 8 sheathing with 10% waste. Stood vertically, six full sheets cover it exactly; the seventh covers mistakes and the cut-up pieces around openings.

How to work it out

  1. 24 ft × 8 ft = 192 sq ft
  2. 192 sq ft × 1.1 waste ÷ 32 sq ft per sheet = 6.6 → 7 sheets

Garage and shed walls are often exactly 8 ft tall, so vertical sheets need no horizontal seams. Enter the area of any doors and windows in the openings field — but keep the offcuts, since headers and small gaps eat them.

Adjust for your project

ft
ft
More options: × · Openings · Waste allowance …
e.g. 2 for both sides of a gable roof
sq ft
Doors, windows, stair holes
%
$
Sheets to buy7 sheets4 × 8 ft
Full-sheet layout count (no offcut reuse)
6 sheets · 4 × 8 ft
Area to cover
192 sq ft
  • Subfloor and roof sheathing run with the long edge across the joists or rafters, and end joints must land on framing — on small or odd-shaped areas that can push waste above 10%.

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Circular saw (7¼ in)A circular saw run along a clamped straightedge breaks sheets down cleanly — score the cut line or use a fine blade to limit splintering.
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Sheets for a 24 × 8 ft wall by area of openings

Sheets for a 24 × 8 ft wall by area of openings
Openings to subtract (total)Area to coverSheets to buy
0 sq ft192 sq ft7 sheets
20 sq ft172 sq ft6 sheets
35 sq ft157 sq ft6 sheets
50 sq ft142 sq ft5 sheets

What to know about sheathing a 24 ft wall

  • Four-foot sheets land on the studs. Forty-eight inches is a multiple of both 16 and 24 in, so with the studs laid out from the corner every vertical sheet edge falls on a stud. Check the first sheet for plumb — every other sheet follows it.
  • An “8 ft” wall is taller than 8 ft. Built with 92⅝ in precut studs, a bottom plate and a double top plate, the frame stands about 97⅛ in. An 8 ft sheet leaves a strip uncovered, so many builders use 9 ft sheets that lap down over the rim or sill, or fill the gap with a ripped strip.
  • Cut openings out after the sheet is up. Sheathing run straight over a window or door and cut out afterwards is stronger and faster than piecing small bits around it. The waste allowance and the openings field together cover what comes out.
  • Nailing is set by code. Nail size and spacing at panel edges and in the field are structural details — follow your local code and the panel stamp.

Finishing the inside of the same wall? The spacing math for trim is in Board and batten spacing for a 12 ft wall. For a floor, see How many sheets of plywood for a 12x12 floor, or in metric sizes How many sheets for a 4 × 3 m floor.

Different size? Use the full Plywood Calculator.

What you’ll need

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Frequently asked questions

How many sheets of OSB for a 24 ft wall with a door and a window?

About 6 sheets if the openings total 35 sq ft (a 3 × 7 ft door and a 3½ × 4 ft window) — 157 square feet to cover, with 10% waste.

How many sheets to sheathe a 24 ft wall 9 ft high?

7 sheets of 4 × 9 ft sheathing with 10% waste for 216 square feet — six stood vertically, one spare.

How many sheets of sheathing for all four walls of a 24x24 garage?

27 sheets of 4 × 8 for four 24 × 8 ft walls before subtracting openings. Take off the garage door and windows in the openings field and the count drops.

Other common sizes

Sources