Walls & paint
Paint & wall calculators
Walls are measured as length × height, minus the doors and windows — and every product covers a different amount per litre, roll, sheet or bag. These calculators do that sum for paint, wallpaper, drywall and plasterboard, wall panels, plaster, insulation and sealant.
Coverage figures are filled in on the safe side and stay editable, so you can type the number printed on your tin, roll or bag. Results come in litres and gallons, metres and feet, and you can download them as a PDF for the shop.
Pick a calculator
- Paint calculatorLitres, gallons and tins of paint for walls and ceiling, plus primer and putty.
- Wallpaper calculatorRolls of wallpaper, including pattern repeat.
- Drywall / plasterboard calculatorSheets of drywall or plasterboard for walls and ceiling.
- Wall panelling calculatorHow many wall panels, slat panels, tongue-and-groove boards or sheets you need for a wall.
- Plaster calculatorBags of skim or undercoat plaster, or cement and sand for cement plaster, for walls or a room.
- Insulation calculatorInsulation thickness for a target R-value, and the rolls, batts or boards to buy.
- Caulk calculatorCartridges or tubes of caulk or sealant for a joint, from its length, width and depth.
Which calculator do I need?
- How much paint do I need for a room?Paint calculator
- How many rolls of wallpaper, with the pattern repeat?Wallpaper calculator
- How many sheets of drywall or plasterboard?Drywall / plasterboard calculator
- How many wall panels or tongue-and-groove boards?Wall panelling calculator
- How many bags of plaster, or cement and sand for rendering?Plaster calculator
- How thick should insulation be, and how many rolls?Insulation calculator
- How many tubes of caulk or silicone sealant?Caulk calculator