Paint Calculator

Work out how many litres of paint your walls need, including coats.

Your details

Room perimeter(m)

Wall height(m)

Doors & windows area(m²)

Coats2

Coverage per litre(m²/L)

Price per litre($)

Most emulsions cover 10–12 m² per litre per coat. Porous or dark surfaces need more.

Formula

litres = (perimeter × height − openings) × coats ÷ coverage

A room with a 20 m perimeter and 2.6 m walls needs about 8.4 L for two coats.

Do I need a primer?

Yes on bare plaster, patched areas or when covering a much darker colour.

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