PAINT

Paint Calculator: How Many Litres Do I Need?

Calculate paint in litres from area, coats and the coverage on your tin, with the best combination of 20, 10, 4 and 1 litre tins.

Surface

Room length

Room width

Wall height

Identical rooms

Doors per room

Windows per room

Include ceiling?

Paint

Coats

Coverage

sq ft/L

sq ft per litre per coat. Check the tin: coverage differs by product and surface.

Wastage

Assumptions used EDIT ▾

Area of one door

sq ft

A 7 × 3 ft door is 21 sq ft.

Area of one window

sq ft

A 4 × 4 ft window is 16 sq ft.

Wall area = 2 × (length + width) × height, for each room, minus openings. Quantity = area × coats ÷ coverage, plus wastage. Coverage varies with the product, surface texture and how absorbent the wall is, so the figure on your tin or bag is the one to use.

Live viewDrawn to scale

PAINT NEEDED

8.5litres

Buy: 2 × 4 L + 1 × 1 L

Area to cover: 403 sq ft
Coats: 2

Paint needed8.5 litres

How it’s calculated

Litres = area × coats ÷ coverage per litre, plus wastage

Example: 403 sq ft × 2 coats ÷ 100 sq ft/L + 5% ≈ 8.5 L → buy 2 × 4 L + 1 × 1 L tins.

Estimates for planning, based on the assumptions shown. They are not a guarantee of quantities or professional engineering advice; check critical work with a qualified professional.