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Drywall sheet chart
Put your area and sheet coverage in: 400 sq ft at 10% waste with 32 sq ft sheets needs 13.75 sheets exact, order 14.
★ CONSTRUCTION · DRYWALL · SHEET CHART
Drywall Sheet Chart: 14 Sheets for a 400 Sq Ft Area
On the defaults — a 400 sq ft area at 10% waste with 32 sq ft drywall sheets — you need 13.75 sheets exact: order 14 sheets. This is the SHEET-SIZE version — the lookup table across 24, 32 and 48 sq ft sheets — the plywood-sheet-chart page is the PLYWOOD version — the same waste-and-round-up model on sheet goods; the drywall-coverage-chart page is the WASTE-ADJUSTABLE version — the same area with a waste percentage you set yourself; and the insulation-roll-chart page is the ROLL version — rolls counted by coverage instead of sheets.
What does 13.75 sheets, order 14, mean?
It means that a 400 sq ft area, once a 10% waste allowance is added, needs 440 sq ft of drywall, and at 32 sq ft a sheet that is exactly 13.75 sheets — so you order 14 sheets, because a partial sheet cannot be bought and the 0.75 of a sheet is a real piece of board. The waste allowance is the whole story in miniature: without it the same area would need exactly 12.50 sheets, so the allowance is worth 1.25 sheets here, and a careless order of 13 sheets would leave 24 sq ft — most of a sheet — uncovered. The part people get wrong is rounding the exact figure twice: 13.75 already includes the waste, so ordering 15 “just in case” adds a second, hidden allowance, and on a bigger job that habit quietly buys a sheet too many on every order.
Three things to check before you trust the number
Is 32 sq ft really your sheet’s coverage? Sheet coverage is width times length, and the standard 4-foot by 8-foot sheet is exactly 32 sq ft — but sheets also come 4 by 10, 4 by 12 and 4 by 14. The 24 sq ft branch needs 18.33 sheets, order 19, and the 48 sq ft branch needs 9.17, order 10, so a wrong coverage figure moves the order by whole sheets. Read the sheet size, multiply width by length, and use that figure.
Is 10% waste enough for your layout? Ten percent covers straight walls with ordinary cutting, but rooms full of doors, windows, outlets and odd angles can push real waste to 15% or 20%, and every extra 10% on 400 sq ft is another 40 sq ft, or more than one more sheet. The 800 sq ft branch orders 28 sheets, so on a large area a waste error compounds fast. If your layout is cut up, price the job at 15% waste first and compare.
Are you boarding one side or both sides of the wall? This page counts one layer over the area you enter. Boarding both sides of a stud wall doubles the sheets: two sides over 400 sq ft need 28 sheets, not 14, and the lookup table below is per side. If your job boards both sides, run the page once per side or double the order — do not let a single-side figure order half a job.
Worked example
On the defaults: 400 sq ft area, 32 sq ft sheet coverage, 10% waste allowance.
- Needed area: 400 × 1.10 is 440 sq ft.
- Exact sheets: 440 ÷ 32 is 13.75 sheets.
- Order: 13.75 rounded up is 14 sheets — a partial sheet cannot be bought, so the 0.75 is a whole sheet.
And the other way: the area needing exactly 13.75 sheets at 32 sq ft a sheet is 400 sq ft, the sheet coverage needing exactly 13.75 sheets over 400 sq ft is 32 sq ft, and the area needing exactly 27.50 sheets at 32 sq ft a sheet is 800 sq ft.
Every branch, checked
- 200 sq ft area, 32 sq ft sheets: 200 sq ft area, 32 sq ft sheets: 6.88 sheets exact — order 7 sheets.
- 800 sq ft area, 32 sq ft sheets: 800 sq ft area, 32 sq ft sheets: 27.50 sheets exact — order 28 sheets.
- 400 sq ft area, 24 sq ft sheets: 400 sq ft area, 24 sq ft sheets: 18.33 sheets exact — order 19 sheets.
- 400 sq ft area, 48 sq ft sheets: 400 sq ft area, 48 sq ft sheets: 9.17 sheets exact — order 10 sheets.
- 100 sq ft area, 32 sq ft sheets: 100 sq ft area, 32 sq ft sheets: 3.44 sheets exact — order 4 sheets.
- 1,000 sq ft area, 32 sq ft sheets: 1,000 sq ft area, 32 sq ft sheets: 34.38 sheets exact — order 35 sheets.
The reverses, worked backwards
- Area needing exactly 13.75 sheets at 32 sq ft a sheet: 400 sq ft — at 400 sq ft the figures are 13.75 sheets exact — order 14 sheets.; at the lower neighbor the figures are 12.03 sheets exact — order 13 sheets.; at the upper neighbor the figures are 15.47 sheets exact — order 16 sheets..
- Sheet coverage needing exactly 13.75 sheets over 400 sq ft: 32 sq ft — at 32 sq ft the figures are 13.75 sheets exact — order 14 sheets.; at the lower neighbor the figures are 15.71 sheets exact — order 16 sheets.; at the upper neighbor the figures are 12.22 sheets exact — order 13 sheets..
- Area needing exactly 27.50 sheets at 32 sq ft a sheet: 800 sq ft — at 800 sq ft the figures are 27.50 sheets exact — order 28 sheets.; at the lower neighbor the figures are 25.78 sheets exact — order 26 sheets.; at the upper neighbor the figures are 29.22 sheets exact — order 30 sheets..
What the defaults assume
The defaults are a 400 sq ft area, 32 sq ft sheets and a 10% waste allowance, so the headline is a single room boarded in one layer of standard 4-by-8 sheets. The model is a multiplication, a division and a ceiling: needed area is area times 1.10, exact sheets are needed area divided by sheet coverage, and the order rounds exact sheets up to the next whole sheet, with a 1e-9 epsilon so an exact whole number orders exactly that many. The area reverse is checked at 50 sq ft either side, because 50 sq ft times 1.10 over 32 sq ft is about 1.72 sheets; the sheet reverse is checked at 4 sq ft either side, because 440 over 28 is 15.71 sheets and over 36 is 12.22; the 800 sq ft reverse is checked at 50 sq ft either side, because 50 sq ft times 1.10 over 32 sq ft is about 1.72 sheets. The model does not include offcut reuse, double-sided boarding, ceiling waste from joist spacing, or fastener, tape and joint-compound quantities — count those separately.
Lookup table: sheets by area and sheet size
Each row already includes the 10% waste allowance: needed area is the area times 1.10, exact sheets are needed area divided by sheet coverage, and the order column rounds up. A row that lands exactly on a whole number orders exactly that many — no extra sheet is added for an exact fit.
| Area | Sheet coverage | Needed area | Exact sheets | Order |
|---|---|---|---|---|
| 100 sq ft | 24 sq ft | 110 sq ft | 4.58 | 5 sheets |
| 100 sq ft | 32 sq ft | 110 sq ft | 3.44 | 4 sheets |
| 100 sq ft | 48 sq ft | 110 sq ft | 2.29 | 3 sheets |
| 200 sq ft | 24 sq ft | 220 sq ft | 9.17 | 10 sheets |
| 200 sq ft | 32 sq ft | 220 sq ft | 6.88 | 7 sheets |
| 200 sq ft | 48 sq ft | 220 sq ft | 4.58 | 5 sheets |
| 300 sq ft | 24 sq ft | 330 sq ft | 13.75 | 14 sheets |
| 300 sq ft | 32 sq ft | 330 sq ft | 10.31 | 11 sheets |
| 300 sq ft | 48 sq ft | 330 sq ft | 6.88 | 7 sheets |
| 400 sq ft | 24 sq ft | 440 sq ft | 18.33 | 19 sheets |
| 400 sq ft | 32 sq ft | 440 sq ft | 13.75 | 14 sheets |
| 400 sq ft | 48 sq ft | 440 sq ft | 9.17 | 10 sheets |
| 500 sq ft | 32 sq ft | 550 sq ft | 17.19 | 18 sheets |
| 600 sq ft | 32 sq ft | 660 sq ft | 20.63 | 21 sheets |
| 800 sq ft | 32 sq ft | 880 sq ft | 27.50 | 28 sheets |
| 1,000 sq ft | 32 sq ft | 1,100 sq ft | 34.38 | 35 sheets |
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Needed area | area × 1.10 | 440 sq ft — 400 × 1.10. |
| Exact sheets | needed area ÷ sheet coverage | 13.75 sheets — 440 ÷ 32. |
| Order | exact sheets rounded up | 14 sheets — 13.75 rounds up. |
| Area needing exactly 13.75 sheets | exact sheets × sheet coverage ÷ 1.10 | 400 sq ft — 13.75 × 32 ÷ 1.10. |
| Sheet coverage needing exactly 13.75 sheets | needed area ÷ exact sheets | 32 sq ft — 440 ÷ 13.75. |
| Area needing exactly 27.50 sheets | exact sheets × sheet coverage ÷ 1.10 | 800 sq ft — 27.50 × 32 ÷ 1.10. |
| 200 sq ft area, 32 sq ft sheets | same model | 6.88 sheets exact — order 7 sheets. |
| 800 sq ft area, 32 sq ft sheets | same model | 27.50 sheets exact — order 28 sheets. |
| 400 sq ft area, 24 sq ft sheets | same model | 18.33 sheets exact — order 19 sheets. |
| 400 sq ft area, 48 sq ft sheets | same model | 9.17 sheets exact — order 10 sheets. |
| 100 sq ft area, 32 sq ft sheets | same model | 3.44 sheets exact — order 4 sheets. |
| 1,000 sq ft area, 32 sq ft sheets | same model | 34.38 sheets exact — order 35 sheets. |
| Area needing exactly 13.75 sheets at 32 sq ft a sheet | reverse | 400 sq ft: 13.75 sheets exact — order 14 sheets. |
| Sheet coverage needing exactly 13.75 sheets over 400 sq ft | reverse | 32 sq ft: 13.75 sheets exact — order 14 sheets. |
| Area needing exactly 27.50 sheets at 32 sq ft a sheet | reverse | 800 sq ft: 27.50 sheets exact — order 28 sheets. |
| 0 sq ft area | same model | 0.00 sheets exact — order 0 sheets. |
| Negative area | same model | Area — 0 or more. |
| Negative sheet coverage | same model | Sheet coverage — more than 0. |
| 400 sq ft area, 44 sq ft sheets | same model | 10.00 sheets exact — order 10 sheets. |
Who uses this
- A DIYer boarding a room — 400 sq ft at 10% waste with 32 sq ft sheets is 14 sheets, with the lookup table covering every other room size and sheet size without re-measuring.
- A contractor ordering for a job — the branches show how the order moves with area and sheet size, so a supplier substitution from 32 to 48 sq ft sheets is repriced before ordering.
- A homeowner comparing sheet sizes — the 24 and 48 sq ft branches show whether the bigger sheet actually saves sheets or just changes the rounding.
- An estimator checking a quote — the reverses recover the area or sheet size behind any quoted sheet count, which checks a quote without re-measuring the job.
Accuracy & limitations
Figures are the model’s own arithmetic on the numbers you type, computed from unrounded values and displayed rounded HALF_UP to 2dp, with orders rounded up using a 1e-9 epsilon so exact fits are not over-ordered. The main limitation is the waste allowance, not the arithmetic: cut-up layouts waste more than 10%, and sheet coverage varies by product, so check the sheet size. This page is a calculation tool, not building advice — follow local code for fire ratings, moisture resistance and fastening.
Cite this calculator
A 400 sq ft area at 10% waste with 32 sq ft drywall sheets needs 13.75 sheets exact: order 14 sheets. Source: Bright Side Kit, https://brightoolbox.com/drywall-chart/, accessed 29 October 2026.
Frequently asked questions
How do I find a sheet’s coverage?
Multiply its width by its length in feet: a 4-foot by 8-foot sheet covers 32 sq ft. The figure is usually printed on the bundle label too — if the label and your multiplication disagree, trust the label and check whether the sheet is sold by covered area or by nominal size.
Why 10% waste?
Ten percent is the standard allowance for cutting, fitting around doors, windows and outlets, and end-of-sheet offcuts on straightforward walls. Straight, unobstructed walls waste less; walls full of openings and odd angles waste more — price cut-up layouts at 15% or higher.
What if the exact figure is already a whole number?
Then you order exactly that many: 10.00 sheets orders 10, not 11. The waste allowance is already inside the exact figure, so adding another sheet for luck double-counts the allowance. The 44 sq ft edge shows this: 440 divided by 44 is exactly 10.00, order 10.
Do I double the order for both sides of a wall?
Yes: this page counts one side. Two sides over the same area need twice the sheets, so a 400 sq ft wall boarded both sides orders 28 sheets, and the lookup table below is per side.
What about ceilings — is the waste the same?
Ceilings often waste more than walls, because joist spacing and light fixtures create more offcuts, and long sheets are harder to handle overhead. If your ceiling layout is cut up, price it at 15% waste first and compare with the 10% figure before ordering.
What about cutting waste around doors and windows?
That waste is what the 10% allowance is for, but it is an average, not a guarantee. On a wall with many openings, measure one wall, count its offcuts, and scale the waste percentage to what you actually see before ordering for the whole job.