Plywood and Sheathing Calculator: Sheets, Nails and Clips
Area, what the sheets are for and the framing spacing, and it returns the sheet count with the fastener schedule behind it. The nail count is the real schedule, six inches around the edges and twelve in the field, rather than a pound per square figure copied off a chart.
When the figures look right, the sheathing material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.
Worked example
These are the figures the calculator opens with and the answer it gives. Change anything above and every number below moves with it.
- Length of the area40 ft
- Width or height8 ft
- What it is forWall sheathing
- Framing spacing16 in on center
- Openings to deduct0 sq ft
- Waste allowance10 %
Sheets to buy11 sheets
| Gross area | 320 sq ft |
|---|---|
| Openings deducted | 0 sq ft |
| Net area | 320 sq ft |
| One sheet covers | 32 sq ft4 by 8 |
| Sheets before waste | 10 |
| Squares | 3.23.125 sheets per square |
| Nails per sheet | 646 in edges, 12 in field at 16 in spacing |
| Nails in total | 7047 lb of 8d common |
| House wrap | 352 sq ftgross wall, ten percent for laps |
The material list this produces
| Sheathing, 4x8 sheets | 11 |
|---|---|
| 8d nails, lb | 8 |
| House wrap, sq ft | 352 |
| Wrap tape, rolls | 1 |
What this calculator assumes
- A sheet is 4 by 8, which is 32 square feet, so three and an eighth sheets cover a square.
- Openings come off in full here, not at half. A window hole in a sheathed wall is a real hole and the offcut around it is what the waste line is for.
- The nail count is the fastener schedule rather than a rule of thumb: six inches around every edge and twelve inches into the framing in the field, so a sheet at 16 inch spacing takes 64 nails and one at 24 inch spacing takes 56. Eight penny common runs about 100 nails to the pound.
- Subfloor adhesive is figured on the linear feet of joist under the sheets, at about 84 feet of quarter inch bead from a 28 ounce tube, which is the size subfloor adhesive actually comes in.
- Roof sheathing wants H clips in each bay along the unsupported joint between rafters, which is four per sheet at 24 inches on center. At 16 inches most panel thicknesses do not need them, so the list leaves them off below 19.2 inch spacing.
- A subfloor gets screwed rather than nailed on most jobs, so the list carries the same fastener count in number eight screws at about ninety five to the pound and leaves the nail line under it as the alternative. Only one of those two lines gets bought.
- Thickness does not change the count, only the price and the span rating. Check the panel span rating against your framing spacing before you buy the thin one.
The sheet count is the easy half
A sheet is 4 by 8, which is 32 square feet, so three and an eighth sheets cover a square. A 40 by 8 wall is 320 square feet, 10 sheets flat and 11 with ten percent waste. A 28 by 40 floor is 1,120 square feet, 35 flat and 39 with waste.
Openings come off in full rather than at half. A window hole in a sheathed wall is a real hole, and the offcut you cut out of the sheet almost never gets used somewhere else. That is what the waste line is for and why the default sits at ten percent.
Thickness never changes the count, only the price and the span rating. Half inch and five eighths cover the same 32 square feet, so check the panel span rating against your framing spacing before you buy the thin one, not after the count is done.
Nails come off the schedule, not a chart
Six inches around every edge of a 4 by 8 is 48 nails. Twelve inches into the framing in the field adds 8 for each intermediate support the sheet crosses, which is two supports at 16 inch spacing and one at 24. So a sheet is 64 nails at 16 inch and 56 at 24.
That turns into weight at about 100 eight penny common to the pound. A 40 by 8 wall is 704 nails and 7 pounds. A 30 by 20 roof at 16 inch spacing is 1,344 nails and 13.4 pounds, and the same roof at 24 inch is 1,176 and 11.8, because the sheet count did not change but the field nailing did.
A pound per square figure would have given the same answer for both of those roofs, which is the reason this page does not use one. The schedule is also what an inspector reads, so a list built from the schedule is a list you can defend.
What changes when you tell it the use
A roof at 24 inch spacing wants H clips in the unsupported joint between rafters, four per sheet, so that 30 by 20 roof takes 84 of them. At 16 inch spacing most panel thicknesses do not need them and the row says so instead of quietly printing a number.
A subfloor gets adhesive on the joists, and the tube count comes off linear feet of joist rather than sheets. That 28 by 40 floor at 16 inch spacing has 840 feet of joist under it and takes 10 tubes, at roughly 84 feet of quarter inch bead from a 28 ounce tube, which is the size subfloor adhesive is actually sold in.
A wall gets house wrap on the gross area with ten percent for laps, 352 square feet on that 40 by 8, plus a roll of tape. A roof gets underlayment the same way, 660 square feet on the 30 by 20. None of those three lines appear on the other two uses.
Screws or nails on a subfloor, and only one of them
A subfloor is screwed on most jobs rather than nailed, so the list carries the same fastener count in number eight screws at about ninety five to the pound. On that 28 by 40 floor it is 27 pounds of screws against 25 pounds of ring shank nails.
The two lines sit next to each other on the material list with the word or between them, because buying both is the mistake this is built to avoid. It is the same trap as ordering bagged mortar mix and masonry sand together on a brick job.
Ring shank is worth naming when you do nail a floor. A smooth shank nail backs out of a joist as the framing dries and that is where a squeaky floor comes from. Adhesive plus a ring shank fastener is what keeps it quiet, and neither one on its own does the job.
Questions people ask
How many sheets of plywood do I need?
Divide the area by 32, then add waste. A 40 by 8 wall is 320 square feet, so 10 sheets flat and 11 with ten percent. A 28 by 40 subfloor is 1,120 square feet, so 35 flat and 39 with waste.
How many nails per sheet of plywood?
Sixty four at 16 inch framing spacing and 56 at 24 inch. That is 48 around the edges at 6 inches plus 8 into each intermediate support at 12 inches in the field. Eight penny common runs about 100 to the pound.
Do I need H clips on roof sheathing?
At 24 inch rafter spacing, yes, four per sheet in the unsupported joint between rafters, so a 30 by 20 roof takes 84. At 16 inch spacing most panel thicknesses do not need them, and the calculator leaves them off below 19.2 inch spacing.
How much subfloor adhesive do I need?
About one 28 ounce tube for every 84 linear feet of joist, because that is roughly what a quarter inch bead gets out of a tube. A 28 by 40 floor at 16 inch joist spacing has 840 feet of joist under it and takes 10 tubes.
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Common sizes, worked out
The same calculator with the numbers already filled in, one page per size, each ending in its own material list.