Finishes
Ceiling calculator
This calculator works out what a ceiling needs: gypsum boards or PVC strips to cover it, the brandering (the timber battens the ceiling is fixed to) and the cornice that finishes the edge. Enter the room size and choose the ceiling type.
What you need
This calculator works out the figures in your browser, which needs JavaScript switched on. The method below shows how to work it out by hand.
Estimates for planning and budgeting. Real quantities depend on the site and the workmanship, so check with your builder before you order.
Gypsum boards are commonly 1,200 mm wide and come in several lengths; PVC ceiling strips are usually 250 mm wide in 6 m lengths. Brandering is typically 38 × 38 mm timber fixed under the trusses at about 400 mm centres for boards and 600 mm for PVC.
The figures are for a single flat ceiling. Bulkheads, coffers and downlights add cutting and timber; allow extra if you have them.
How it is worked out
- Ceiling area = length × width.
- Boards = area ÷ board area, plus waste, rounded up. PVC strips = rows across the room × strips per row.
- Brandering = rows across the room at the chosen spacing × room length.
- Cornice = perimeter, plus waste.
What it assumes
- Brandering runs across the trusses in one direction.
- Screws, nails, joint tape and cornice adhesive are not included.
Common questions
How many gypsum boards for a 4 by 4 room?
The ceiling is 16 m². A 1.2 × 2.4 m board covers 2.88 m², so about 6 boards, or 7 with cutting waste.
What spacing for brandering?
About 400 mm centres for 9 mm gypsum board and about 600 mm for PVC strips. Follow the board manufacturer.
Is PVC or gypsum better?
Gypsum gives a seamless, paintable ceiling and better fire resistance; PVC is quicker to install and washable, and needs no painting.
Want exact quantities for your plan?
A calculator works one wall or one slab at a time. A bill of quantities works from your actual drawings and counts everything, which is what builders price against and what stops you buying twice.