Paint Coverage Calculator

Work out how many litres of paint you need for your walls, ceilings, or woodwork.

Calculate Paint Needed

Measure wall/ceiling length × height, subtract windows and doors. Or use our measuring guide.

Coverage rates used (per coat, as of July 2026): Emulsion 11 m²/litre, gloss/satinwood 15 m²/litre, masonry 5 m²/litre. These are deliberately conservative averages. Manufacturers such as Dulux and Crown quote up to 12-16 m²/litre for emulsion and gloss on smooth surfaces, but real coverage is lower on bare or porous surfaces. Masonry is set low because exterior walls are usually textured and porous. Calculation includes a 10% wastage allowance. Always buy slightly more than calculated.

How This Calculator Works

This paint calculator uses industry-standard coverage rates from UK paint manufacturers:

  • Emulsion (walls/ceilings): 11 m² per litre per coat
  • Gloss/satinwood (woodwork): 15 m² per litre per coat
  • Exterior masonry: 5 m² per litre per coat

The calculator automatically adds a 10% wastage allowance to account for uneven surfaces, roller loss, and application variations.

When to Use 1, 2, or 3 Coats

  • 1 coat: Refreshing the same colour on previously painted surfaces in good condition
  • 2 coats: Most situations (recommended for even finish and durability)
  • 3 coats: Covering dark colours with light paint, or bare plaster/wood

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