Free UK fixing quantity tool

Plasterboard Screw Calculator

Work out how many plasterboard screws to allow for from a known sheet count and the fixing count required by your actual wall or ceiling system.

No fixed screws-per-sheet assumption0% spare allowance by defaultOptional pack rounding
Plasterboard and drylining illustration

Estimate your plasterboard screws

Enter the number of boards and the fixing count per sheet from the drawing, specification, manufacturer system or fixing layout you are actually using.

sheets
Use the whole-board quantity you plan to fix.
screws
Use the count required by your chosen system/layout. We do not impose a universal default.
%
Optional spares only. Set your own allowance; 0% is the neutral default.
screws
Enter the actual box/pack quantity to calculate whole packs to buy.
Why no default fixing count? Fixing centres vary with the wall, ceiling or encasement system. Use the fixing schedule that applies to the job, then let this calculator handle quantity and pack rounding.
Enter your sheet count and fixing count per sheet.The calculator does not impose a universal screw-spacing pattern or screws-per-sheet figure.

How to calculate how many plasterboard screws you need

This calculator deliberately separates the fixing specification from the quantity arithmetic. First establish the fixing pattern required by the exact system you are installing. Then count the fixings that pattern gives per full board and enter that number above.

Base screw quantity = plasterboard sheets × fixings per sheet. Optional spare screws are added afterwards, then pack rounding is applied only if you enter the real pack size.
1. Get the board quantity

Use the sheet count from your take-off or our Plasterboard Calculator.

2. Use the actual fixing pattern

Take screw centres and fixing-line requirements from the applicable system, drawing or manufacturer guidance.

3. Round commercially

If your merchant sells boxes of a fixed quantity, enter that quantity to see whole packs and the resulting surplus.

Why there is no universal “screws per plasterboard” number

Walls, ceilings, encasements, board layers, support layouts and proprietary systems can require different fixing arrangements. A convenient internet rule-of-thumb can therefore be the wrong specification for the job.

Primary-source check: British Gypsum’s current technical support guidance gives different general fixing centres for partitions, ceilings and encasements and explicitly says these can vary by system. Check the British Gypsum fixing-centres guidance.

Quantity tool, not a fixing specification. This calculator does not choose screw length, screw type, fixing centres, board orientation, support spacing or the correct lining system. Follow the project specification and current manufacturer system details.

Worked quantity example

Example only: suppose your approved fixing layout works out at 28 screws per full sheet and the take-off contains 18 sheets.

Base quantity = 18 × 28 = 504 screws. With a user-selected 5% spare allowance, the calculator adds 26 screws and gives 530 screws to allow for. If the actual box contains 1,000 screws, pack rounding gives one box with 470 screws left beyond the calculated allowance.

Common plasterboard screw estimating mistakes

  • Using a generic screws-per-sheet figure instead of the fixing pattern for the actual system.
  • Assuming a wall and ceiling use the same fixing centres.
  • Choosing screw length from a quantity calculator rather than the board build-up and substrate.
  • Adding a hidden 10% spare allowance without showing it.
  • Forgetting that screws are purchased in real pack quantities.

Frequently asked questions

How many screws do I need per plasterboard sheet?

There is no safe universal quantity. Establish the fixing lines and centres required by the system you are installing, count the fixings for one board, then enter that number in the calculator.

Does the calculator choose plasterboard screw spacing?

No. Fixing centres are a specification decision and can differ between wall, ceiling and encasement systems. This tool only converts your chosen fixing pattern into a purchase quantity.

Should I add extra screws?

That is a purchasing choice rather than a universal rule. The allowance starts at 0%; if you want spare fixings for losses or contingencies, enter the percentage you want to carry.

Can I calculate how many boxes of screws to buy?

Yes. Enter the actual number of screws in the pack you are buying and the calculator rounds the required screw quantity up to whole packs.

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