Paint Calculator

Calculate exactly how many litres of paint and how many tins you need for any project.

Enter your measurements

Total Surface Area m²

Number of Coats

Results

Total Litres Needed5.0 L

4-litre tins2

20-litre tins1

Coverage ~12 m²/litre on smooth primed plaster; rough blockwork: 6–8 m²/litre

How it works

Total paint equals (area × coats) ÷ coverage rate. Standard emulsion paint covers approximately 12 m² per litre on smooth primed plaster. On rough or unpainted blockwork the coverage drops to 6–8 m²/litre. Results are shown in 4L and 20L tin quantities to help you choose the most economical pack size.

Formula

Litres = (Area × Coats) / Coverage (12 m²/L)
4L tins = ceil(Litres / 4)
20L tins = ceil(Litres / 20)

Tips for accurate results

1Add 10% extra for wastage, touch-ups and uneven surface absorption.

2On new plaster, apply a mist coat (diluted 20% water) before full coats to prevent adhesion failure.

3Calculate ceiling paint (white matt emulsion) separately from wall paint.

4External masonry paint is thicker — expect 6–8 m²/litre; always check the stated coverage on the tin.

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