Brushup

Measure the room, pick your coats, and Brushup works out the litres and the tins to buy with the least left over.

The room

Length (m) Width (m) Wall height (m)

Doors Windows Coats

Wall paint Price per litre (optional)

Big colour change (dark to light)

Also painting?

Ceiling

Woodwork (skirting, doors, frames)

How it reads

Wall area is the room's perimeter times its height, less the door and window openings. Litres are area × coats ÷ spread rate, where the spread rate is how far a litre goes in one coat — about 12 m² per litre for emulsion, less for primer and exterior masonry, more for trim paint. Brushup adds a touch-up allowance on top and rounds up to whole tins, choosing the tins that leave the least paint over.

Two coats is the norm. One coat only covers when you're going over the same colour in good condition; a big colour change often wants three, or a tinted primer first. The ceiling is its own tin (its area is just the floor), and woodwork uses gloss or satinwood, not wall paint, so that's separate too.

Spread rates shown are typical; the exact figure is on the tin and depends on the surface — bare plaster soaks up the first coat. Figures follow Dulux and Crown product coverage and standard decorating guidance on openings and coats.

Brushup is a buying guide, not a spec. Awkward shapes, heavy texture, sprayers and strong colours all change the real figure, so keep the receipt and a spare tin.