Plasterboard Calculator

Wall and ceiling area in; board count, screws, joint tape and compound out.

Area to board

Board size

BoardingAmount
Boards needed, wastage included
0

Fixings and jointing

Screws0
Joint tape0 m
Joint compound0.0 kg
Compound tubs to buy0

How this calculator works

Total area to board is wall plus ceiling area, with wastage added for cuts around sockets, doors and awkward corners, then divided by the area of one board (length × width, standard sheets are 2400 x 1200mm, giving 2.88 m2 each, though 2700 and 3000mm lengths are also common for taller rooms). Screws are worked out from a grid: a screw goes in wherever a stud or joist line crosses a screw row, so the area covered by one screw is the support centres multiplied by the screw spacing, both editable above, and the total screw count is the boarded area divided by that per-screw area.

Joint tape and compound

Rather than trying to trace every individual board joint, this calculator uses a coverage rate, metres of tape and kilograms of compound per square metre of boarded area, the same approach as the paint calculator's litres-per-square-metre figure. The defaults (1m of tape and 0.5kg of compound per m2) suit a typical two-coat taped and filled finish; a full skim coat over the whole board (rather than just taped joints) uses considerably more compound, so increase the compound rate if that's your plan.

Choosing stud or joist centres

400mm centres are standard for most stud partition walls and ceiling joists in UK domestic work, though 600mm is also common on some ceiling and loft conversions using deeper joists. Check what's actually behind the existing structure, or what you're building to, before relying on the screw count.

What this calculator does not check

This tool covers boarding materials only. It doesn't check fire or sound rating requirements (some walls and ceilings, particularly between properties or around escape routes, need specific board types and thicknesses set by Building Regulations), whether you need moisture-resistant board in a bathroom, or insulation behind the boarding. Check current Building Regulations Approved Document requirements for the specific room and wall type before you board.

Related tools

Painting the finished walls? The paint calculator works out litres and tins. Papering instead? See the wallpaper calculator for roll count.