How plywood weight is worked out
The weight of a plywood sheet is the area in square feet times the thickness in feet times 35 pounds a cubic foot, which is the nominal density of softwood plywood. The thickness in inches is divided by 12 to get feet, so a 3/4 in sheet is 0.75 ÷ 12 = 0.0625 ft thick. The sheet area is the width times the height, so a 4x8 sheet is 4 × 8 = 32.00 sq ft. The sheets needed are the project area times one plus the waste, divided by the sheet area and rounded up, because a part sheet still has to be bought whole. The total weight is the sheets times the weight per sheet.
At the defaults — 3/4 in, 4x8, 100 sq ft, 10% waste — the sheet area is 4 × 8 = 32.00 sq ft, the weight per sheet is 32.00 × (0.75 ÷ 12) × 35 = 70.00 lb, the area needed is 100 × 1.10 = 110.00 sq ft, the sheets are 110.00 ÷ 32.00 = 3.44, rounded up to 4 sheets, and the total weight is 4 × 70.00 = 280.00 lb.
| Thickness | Millimetres | Weight per 4x8 sheet | Common uses |
|---|
| 1/4 in | 6.4 mm | 23.33 lb | underlayment, cabinet backs |
| 3/8 in | 9.5 mm | 35.00 lb | wall sheathing, soffits |
| 1/2 in | 12.7 mm | 46.67 lb | wall sheathing, subfloor |
| 5/8 in | 15.9 mm | 58.33 lb | subfloor, roof decking |
| 3/4 in | 19.1 mm | 70.00 lb | subfloor, shelving |
| 7/8 in | 22.2 mm | 81.67 lb | heavy subfloor |
| 1 in | 25.4 mm | 93.33 lb | workbench tops, specialty |
This is a size and weight chart, and it is not a veneer-grade or span-rating chart: it does not say which grade of face veneer a sheet has, and it does not say how far a sheet can span between joists. Actual weight varies by about ±15% by species and moisture: a sheet that has been stored damp weighs more, and a hardwood plywood sheet weighs more than a softwood sheet of the same thickness.
The worked example, line by line
Setup: 3/4 in, 4x8, 100 sq ft, 10% waste.
Line 1 — the sheet area. 4 × 8 = 32.00 sq ft.
Line 2 — the thickness in feet. 0.75 ÷ 12 = 0.0625 ft.
Line 3 — the weight per sheet. 32.00 × 0.0625 × 35 = 70.00 lb.
Line 4 — the area needed. 100 × 1.10 = 110.00 sq ft.
Line 5 — the sheets. 110.00 ÷ 32.00 = 3.44, rounded up to 4 sheets.
Line 6 — the total weight. 4 × 70.00 = 280.00 lb.
Every branch, checked
1/2 in 4x8: the weight per sheet is 32.00 × (0.5 ÷ 12) × 35 = 46.67 lb, the sheets stay 4, and the total weight is 4 × 46.67 = 186.67 lb. Thinner plywood is lighter in direct proportion to its thickness: a 1/2 in sheet is two-thirds the weight of a 3/4 in sheet.
5x5 3/4 in: the sheet area is 5 × 5 = 25.00 sq ft, the weight per sheet is 25.00 × 0.0625 × 35 = 54.69 lb, the sheets are 110.00 ÷ 25.00 = 4.40, rounded up to 5 sheets, and the total weight is 5 × 54.69 = 273.44 lb. A smaller sheet weighs less on its own, but more sheets are needed, so the total weight is close to the 4x8 total.
4x10 3/4 in: the sheet area is 4 × 10 = 40.00 sq ft, the weight per sheet is 40.00 × 0.0625 × 35 = 87.50 lb, the sheets are 110.00 ÷ 40.00 = 2.75, rounded up to 3 sheets, and the total weight is 3 × 87.50 = 262.50 lb. A longer sheet covers more area, so fewer sheets are needed, and the total weight falls even though each sheet is heavier.
150 sq ft: the area needed is 150 × 1.10 = 165.00 sq ft, the sheets are 165.00 ÷ 32.00 = 5.16, rounded up to 6 sheets, and the total weight is 6 × 70.00 = 420.00 lb.
150 sq ft, no waste: the area needed is 150 sq ft, the sheets are 150 ÷ 32.00 = 4.69, rounded up to 5 sheets, and the total weight is 5 × 70.00 = 350.00 lb. Dropping the waste saves one sheet here, because 150 sq ft sits just under the 5-sheet line.
500 sq ft: the area needed is 500 × 1.10 = 550.00 sq ft, the sheets are 550.00 ÷ 32.00 = 17.19, rounded up to 18 sheets, and the total weight is 18 × 70.00 = 1,260.00 lb.
500 sq ft, no waste: the area needed is 500 sq ft, the sheets are 500 ÷ 32.00 = 15.63, rounded up to 16 sheets, and the total weight is 16 × 70.00 = 1,120.00 lb. At this size the waste allowance is worth 2 sheets, or 140.00 lb.
Reverse — weight to thickness: a 4x8 sheet that weighs 70.00 lb is 3/4 in, one that weighs 46.67 lb is 1/2 in, one that weighs 35.00 lb is 3/8 in, and one that weighs 93.33 lb is 1 in. Weigh the sheet, and the thickness follows, because the weight is the thickness times the area times 35.
What the defaults assume
The model assumes nominal softwood plywood at 35 lb a cubic foot, with the thickness as marked: a 3/4 in sheet is taken as 0.75 in, although a real sheet is often a little under its nominal thickness. It assumes the sheet area is the width times the height, the waste is spread evenly over the project, and the sheets are rounded up to whole sheets. Actual weight varies by about ±15% by species and moisture, and it does not say which grade of face veneer a sheet has, or how far a sheet can span between joists: this is not a veneer-grade or span-rating chart. Rounding convention: weights to 2 decimals, sheets to whole numbers, and all figures are computed from unrounded values, rounded only for display.
Output · formula · meaning
| Output | Formula | What it means |
|---|
| Sheet area | width × height | 32.00 sq ft. |
| Weight per sheet | area × thickness/12 × 35 | 70.00 lb. |
| Area needed | project area × (1 + waste) | 110.00 sq ft. |
| Sheets needed | ceil(area needed ÷ sheet area) | 4. |
| Total weight | sheets × weight per sheet | 280.00 lb. |
| 1/2 in 4x8 | same model, 1/2 in | 46.67 lb/sheet, 4 sheets, 186.67 lb total. |
| 5x5 3/4 in | same model, 5x5 | 25.00 sq ft/sheet, 54.69 lb/sheet, 5 sheets, 273.44 lb total. |
| 4x10 3/4 in | same model, 4x10 | 40.00 sq ft/sheet, 87.50 lb/sheet, 3 sheets, 262.50 lb total. |
| 150 sq ft | same model, 150 sq ft | 6 sheets, 420.00 lb total. |
| 150 sq ft, no waste | same model, waste 0% | 5 sheets, 350.00 lb total. |
| 500 sq ft | same model, 500 sq ft | 18 sheets, 1,260.00 lb total. |
| 500 sq ft, no waste | same model, waste 0% | 16 sheets, 1,120.00 lb total. |
| Reverse: 70.00 lb sheet | weight ÷ (32 × 35/12) | 3/4 in. |
| Reverse: 46.67 lb sheet | weight ÷ (32 × 35/12) | 1/2 in. |
| Reverse: 35.00 lb sheet | weight ÷ (32 × 35/12) | 3/8 in. |
| Reverse: 93.33 lb sheet | weight ÷ (32 × 35/12) | 1 in. |
Who uses this
- The homeowner sheathing a shed floor: they learn 100 sq ft of 3/4 in plywood needs 4 sheets and weighs 280.00 lb — so they know how many sheets to buy, and they know whether the car can carry them.
- The builder pricing a subfloor: they learn 500 sq ft of 3/4 in plywood needs 18 sheets and weighs 1,260.00 lb — so they know the material count and the delivery weight, and they check the waste at 10%.
- The DIYer carrying sheets upstairs: they learn one 3/4 in 4x8 sheet weighs 70.00 lb, and a 1/2 in sheet weighs 46.67 lb — so they know a 3/4 in sheet is a two-person carry, and they pick the 5x5 sheet at 54.69 lb if they are carrying alone.
- The renovator identifying an old sheet: they learn a 4x8 sheet that weighs 70.00 lb is 3/4 in, and one that weighs 35.00 lb is 3/8 in — so they know the thickness from the bathroom scale, and they match it before they buy.
Accuracy & limitations
The math is exact for the numbers you enter: the weight per sheet is the area times the thickness in feet times 35 lb a cubic foot, the sheets are the area needed divided by the sheet area and rounded up, and the total weight is the sheets times the weight per sheet. What the model cannot do is weigh your sheets for you: weigh one, and check the thickness with a tape, because a real sheet is often a little under its nominal thickness. Actual weight varies by about ±15% by species and moisture, and a hardwood plywood sheet weighs more than a softwood sheet of the same thickness. This is not a veneer-grade or span-rating chart: it does not say which grade of face veneer a sheet has, or how far a sheet can span between joists. For the lumber itself, see lumber size chart; for the screws that hold it, see screw size chart.
Cite this reference tableBright Side Kit. “Plywood Size Chart: Sheet Sizes, Thickness & Weight.” brightoolbox.com, 2026. Method: sheet weight = area (sq ft) × thickness (ft) × 35 lb/ft³ (nominal softwood plywood; actual weight varies ±15% by species/moisture); sheet area = width × height; weight per sheet = sheet area × thickness/12 × 35; sheets = ceil(project area × (1 + waste/100) ÷ sheet area); total weight = sheets × weight per sheet. Table: 1/4 in (6.4 mm) 23.33 lb; 3/8 in (9.5 mm) 35.00 lb; 1/2 in (12.7 mm) 46.67 lb; 5/8 in (15.9 mm) 58.33 lb; 3/4 in (19.1 mm) 70.00 lb; 7/8 in (22.2 mm) 81.67 lb; 1 in (25.4 mm) 93.33 lb per 4x8 sheet. Defaults: 3/4 in, 4x8, 100 sq ft, 10% waste → 32.00 sq ft/sheet, 70.00 lb/sheet, 4 sheets, 280.00 lb total; 1/2 in 4x8 → 46.67 lb/sheet, 4 sheets, 186.67 lb total; 5x5 3/4 in → 25.00 sq ft, 54.69 lb/sheet, 5 sheets, 273.44 lb total; 4x10 3/4 in → 40.00 sq ft, 87.50 lb/sheet, 3 sheets, 262.50 lb total; area 150 sq ft → 6 sheets, 420.00 lb total; area 150 waste 0% → 5 sheets, 350.00 lb total; area 500 sq ft → 18 sheets, 1,260.00 lb total; area 500 waste 0% → 16 sheets, 1,120.00 lb total; reverses: 70.00 lb → 3/4 in; 46.67 lb → 1/2 in; 35.00 lb → 3/8 in; 93.33 lb → 1 in. Not a veneer-grade or span-rating chart. Bright Side Kit. "Plywood Size Chart: Sheet Sizes, Thickness & Weight." https://brightoolbox.com/plywood-size-chart/ Accessed October 25, 2026.
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