Plasterboard Calculator UK – Walls & Ceilings
Work out how many sheets of plasterboard you need for a wall, a ceiling, or a whole room, in metric, to UK board sizes. Enter the room length, width and height, choose whether you're boarding the ceiling too, and the calculator gives you the total area and the number of sheets to order, with a waste allowance built in. It defaults to the standard 2400 × 1200mm UK sheet and takes the other common sizes as well. Plasterboard and drywall are the same material, so if you've searched for a drywall calculator you're in the right place.
Your Results
Sheets (2400×1200mm)
Includes selected waste allowance. Final result rounded up.
How this calculator works
This calculator works out the wall area, ceiling area, or combined area from the room dimensions entered. Wall area is calculated from the full room perimeter multiplied by the wall height. If the ceiling toggle is on, it also adds the ceiling area, which is the room length multiplied by the room width. The total coverage is then divided by the area of one sheet, the waste allowance is applied, and the result is rounded up to give the number of plasterboard sheets to order. The tool defaults to metric (metres) and supports three UK-standard plasterboard sizes: 2400×1200mm, 1800×900mm, and 2700×1200mm. You can switch to imperial (feet) at any time and the sheet areas will convert automatically. Plasterboard and drywall are the same product — drywall is the North American name for what UK builders call plasterboard.
Formulas used
wall area = 2 × (length + width) × height
ceiling area = length × width
total area = wall area + ceiling area
sheets = ⌈(total area ÷ sheet area) × (1 + waste % ÷ 100)⌉
Sheet sizes: 2400×1200mm = 2.88 m², 1800×900mm = 1.62 m², 2700×1200mm = 3.24 m². This tool does not subtract openings such as doors or windows. The final sheet count is always rounded up.
Worked example
Take a 4m × 4m living room with a 2.4m ceiling, boarding the four walls and the ceiling. The perimeter is 16m, so the wall area is 16 × 2.4 = 38.4 m². The ceiling adds 4 × 4 = 16 m², giving 54.4 m² in total. With standard 2400 × 1200mm sheets (2.88 m² each) and a 10% waste allowance, the sum is (54.4 ÷ 2.88) × 1.10 = 20.78, rounded up to 21 sheets. In 2026, a standard 12.5mm board runs roughly £10 to £13 at a merchant like Jewson or Travis Perkins, so that's about £210 to £270 in board before screws and jointing. The calculator doesn't deduct doors or windows, so trim the area down if the room has large openings.
UK plasterboard sizes and types
| Board | Size | Area | Typical use |
|---|---|---|---|
| Standard (12.5mm) | 2400 × 1200mm | 2.88 m² | Everyday walls and ceilings in dry rooms |
| Standard (small) | 1800 × 900mm | 1.62 m² | Easier to lift solo, more joints |
| Standard (tall) | 2700 × 1200mm | 3.24 m² | Taller rooms, fewer horizontal joints |
| Moisture-resistant | 2400 × 1200mm | 2.88 m² | Bathrooms, kitchens, utility (usually green) |
| Fireline | 2400 × 1200mm | 2.88 m² | Garage / fire-rated walls and ceilings (usually pink) |
Plasterboard in the UK is manufactured to BS EN 520. Where a board type is required for fire or sound — for example a garage wall next to living space or a wall between two homes — that comes under the Building Regulations (Approved Document B for fire, Approved Document E for sound) and isn't optional. British Gypsum's Gyproc WallBoard is the standard board most merchants stock.
Why this estimate matters
Estimating wall and ceiling coverage early helps with ordering plasterboard sheets, planning waste, and comparing room options before work begins. It also makes it easier to understand whether the project is mostly wall coverage, ceiling coverage, or a mix of both. New to boarding? Read How Much Plasterboard Do I Need? UK Guide for a full walk-through. This tool is for planning and estimating only and does not replace site measurement or installation planning.
Frequently asked questions
Related tools
- Stud Wall Calculator UK — the timber frame these boards fix to
- Tile Calculator — for tiling the finished wall
- Brick Calculator UK — for a masonry wall instead
- Wallpaper Calculator UK — drop-counting roll estimate with pattern repeat and match type
- All construction tools — the full set of UK calculators
Guides worth reading
- How Many Screws Per Plasterboard Sheet? — spacing, lengths and quantities per board explained
- How Much Plasterboard Do I Need? UK Guide — sheet count, waste allowance and 2026 prices
Disclaimer: This calculator is for planning and estimating only. Actual plasterboard quantities vary with sheet size, waste, openings, cutting layout, and site conditions. Always confirm final requirements before ordering.