Drywall & Plasterboard Calculator — Sheets & Cost
Plan drywall or plasterboard for one or several rooms. Choose US or metric board sizes, separate walls and ceilings, subtract openings and price your order in USD or GBP.
Drywall & plasterboard · whole-panel purchase plan
18 panels13 wall panels + 5 ceiling panels · 10% allowance
Enter your room dimensionsRoom 1 · 472 sq ft
352 sq ft walls + 120 sq ft ceiling
Bars show surface areas, not panel placement or a cutting layout.
1. Measure your rooms
Estimate panels for rectangular rooms. Combine matching wall surfaces across rooms; ceiling panels are ordered separately. Each example replaces all dimensions, panel sizes, currency and quotes. All examples use no deducted openings and 10% allowance; US examples use 4 × 8 ft panels.
Room 1
2. Choose panels and allowance
Add your panel prices and delivery
Use your supplier’s current quotes, all on the same tax / VAT basis. Blank means unknown; enter 0 only when included or free. Changing currency clears all quotes; changing a panel size clears its quote. No currency conversion is applied.
Your panel order
| Surface | Panel size | Net area | Panels to buy |
|---|---|---|---|
| Walls | 4 × 8 ft | 352 sq ft | 13 |
| Ceiling | 4 × 8 ft | 120 sq ft | 5 |
Quoted items subtotal
Enter quotesMissing: wall panel price, ceiling panel price, delivery. This is not a complete project price.
Walls: round up (352 sq ft × 1.1 ÷ 32 sq ft/panel) = 13. Ceiling: round up (120 × 1.1 ÷ 32) = 5, rounded separately.
This is an area-based allowance estimate, not a cutting plan. Check panel suitability, framing, joint layout and carrying access before ordering. Costs exclude compound, tape, fasteners, labor and tax unless already included in your quotes.
Compare panel formats
Each option uses the same dimensions and allowance. Walls and ceilings remain separate orders. A lower sheet count does not automatically mean lower cost or easier installation; quoted prices are not reused across different sizes.
| Panel size | Walls | Ceiling | Total |
|---|---|---|---|
| 4 × 8 ft | 13 | 5 | 18 |
| 4 × 10 ft | 10 | 4 | 14 |
| 4 × 12 ft | 9 | 3 | 12 |
| 1800 × 900 mm | 23 | 8 | 31 |
| 2400 × 1200 mm | 13 | 5 | 18 |
| 3000 × 1200 mm | 10 | 4 | 14 |
Area breakdown by room
| Room | Net walls | Ceiling | Wall openings |
|---|---|---|---|
| Room 1 | 352 sq ft | 120 sq ft | 0 sq ft |
How many sheets of drywall or plasterboard do I need?
For each rectangular room, wall area is 2 × (length + width) × height, minus large wall openings. Ceiling area is length × width. Sum wall areas, add your allowance and divide by the wall panel area, rounding up to a whole panel. Repeat separately for ceilings. A 4 × 8 ft panel covers 32 sq ft; 4 × 10 covers 40; 4 × 12 covers 48. Metric boards use their actual face area: 1800 × 900 mm covers 1.62 m², 2400 × 1200 mm covers 2.88 m² and 3000 × 1200 mm covers 3.6 m². A 2400 × 1200 mm board is smaller than a 4 × 8 ft panel; these are not interchangeable sizes.
Plasterboard example in metres
A 4 × 3 m room with 2.4 m high walls has 33.6 m² of walls and 12 m² of ceiling before openings. With 10% allowance and 2400 × 1200 mm boards, buy 13 wall boards and 5 ceiling boards, 18 in total. Load the UK room example above to edit these values.
Should I subtract doors and windows?
Enter the combined area of large openings, such as doorways and picture windows. Small electrical and pipe cutouts generally do not save a usable sheet. Deductions are estimates: offcuts may not fit another part of the room.
Which sheet size should I choose?
Longer panels can reduce joints, but room dimensions, framing direction and delivery access matter. This comparison counts sheets by area; it does not place seams or prove that every cut can be reused. Keep different panel types and thicknesses in separate orders. If your rooms need different wall products, calculate those groups separately.
What does the price include?
Only selected panels and entered delivery. Blank quotes remain visibly incomplete. This is not a contractor installation estimate. Obtain separate quotes for finishing materials, labor and other work.
Scope and source
This calculator covers one layer per selected surface, level rectangular ceilings and constant wall heights. Sloped ceilings, curved walls, fire-rated assemblies and framing quantities need a project-specific plan. Consult the USG Sheetrock installation guide for measurement and panel-layout guidance and the exact product instructions for your assembly.
Metric face sizes are listed in the British Gypsum Gyproc WallBoard product table (checked 17 September 2026). The format selector specifies face dimensions only; it does not select a suitable thickness or a fire, moisture or acoustic system.
Planning the finish? Use the paint calculator after establishing the surface area and paint coverage.
Before closing the walls, use the insulation package calculator to plan materials from the exact product-label coverage.
