Plasterboard & Drywall Calculator
Add each wall and ceiling as a separate surface
Metric (m)
Imperial (ft / in)
Surfaces
Typical allowance: 10% standard rooms, 15% complex shapes or angled ceilings
Job Costing
Enter costs in your local currency - the calculator works with any currency as long as values are consistent.
UK Market Prices
Fills in the material cost fields with current UK market prices. You can review and edit each price before applying.
Results
| Surface | Type | Area (m²) | Net Boards | Waste | Total |
|---|
Total Area
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m² net (after deductions)
Net Boards
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Before waste
Total to Order
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inc. waste allowance
Board Size
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m² per board
Fixings & Materials Estimate
Screws Required
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Joint Tape
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- rolls
Jointing Compound
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approx. 25kg bags
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Frequently Asked Questions
How many plasterboard sheets do I need per square metre?
One standard sheet (2400 x 1200 mm) covers 2.88 m². Divide your total surface area by 2.88 and add 10-15% waste for cuts around openings and corners. Measure walls and ceiling separately and total them up.
What thickness of plasterboard should I use?
9.5 mm suits ceilings at 400 mm joist centres and lightweight linings. 12.5 mm is the standard for most walls and ceilings. 15 mm and above for enhanced fire or acoustic performance. For fire-rated partitions under Part B, use specialist fire-line board.
What is the standard plasterboard sheet size in the UK?
The standard size is 2400 x 1200 mm, designed to span three studs or joists at 600 mm centres. Smaller 1800 x 900 mm sheets are available for confined spaces. Tapered edge boards are most common as they allow a seamless jointed finish.
How many screws do I need per plasterboard sheet?
Allow approximately 32 screws per standard sheet fixed to timber at 600 mm centres - screws at 150 mm centres around the perimeter and 300 mm in the field. Use 25 mm screws for 9.5 mm board and 32 mm for 12.5 mm board into timber.
What Building Regulations apply to plasterboard?
Plasterboard must comply with Part B (Fire Safety) for party walls and floors, Part E (Sound Insulation) requiring minimum 45 dB Rw between dwellings, and Part L (Energy Efficiency) when used as a thermal lining. Party walls require specific tested board configurations under Approved Document E.
What waste allowance should I use for plasterboard?
Allow 10% waste for straightforward rooms with few openings, and 15% for rooms with multiple doors, windows or complex shapes such as sloped ceilings. Offcuts from openings can sometimes be reused on smaller areas to reduce overall waste.