United Kingdom · square metres / litres / GBP

Paint calculator — walls, coats & containers

Work out wall paint from room dimensions or a measured area. Subtract doors and windows, choose coats and round up to whole containers.

Room walls and ceiling shown separately, with a window deducted from wall area — Measure walls and ceiling separately. Subtract openings from their own surface.

Make your painting plan

1. Measure your surfacesHow will you measure?

Room 1

Length (m)Width (m)Wall height (m)Doors/windows total (m²)Ceiling openings (m²)

Enter total door/window area to subtract, not the number of openings. Each row is a separate room. For an irregular room or individual walls, enter measured paintable areas instead of splitting the floor into rectangles.

Include the ceiling using the same paint and coat countExtra paint allowance (%)

0% is the starting assumption. Adjust for your application and keep coats separate from this allowance.

2. Paint detailsProduct or manual details

Coverage (m²/L)Number of coats

Available container sizes

Keep all sizes the same formulation, colour and finish. Leftover primer cannot replace finishing paint.

Your shopping list will appear here. Review dimensions, coats and the current label before buying.

Multiple rooms share one wall colour and product. Calculate different colours as separate projects. Quantity estimates do not establish primer/topcoat compatibility.

Calculate paintable wall area, not floor area

For a rectangular room, multiply its perimeter by wall height, then subtract the total area of doors and windows. Add separate rooms before calculating containers when they share one paint colour.

A worked wall-paint example

4 × 3 m with 2.4 m walls: 2 × (4 + 3) × 2.4 = 33.6 m² of walls. Subtract 2 m² of openings to get 31.6 m². At 10 m² per litre and two coats, the estimate is 6.32 litres. Three 2.5-litre tins provide 7.5 litres.

Coverage and coats change the result

Paintable m² × coats ÷ coverage per litre
Apply your optional extra allowance, then round to available containers.

Manufacturer ranges use their lower coverage value by default. A quoted “up to” coverage is not a guarantee on every surface. Check porosity, colour change, application method and preparation; adjust the form to your current label.

Are the displayed prices current?

Store prices are dated snapshots. After seven days, product-based costs are withheld; quantities remain available for up to 30 days before specifications also need a refresh. Manual details use the numbers you enter.

Can I mix litres and US gallons?

Choose the matching country tool and label units. A US gallon and an imperial gallon are different. This pilot does not convert a UK product into a US product or combine their offers.

UK paint & primer sample

Recorded coverage is a planning input. Product selection does not approve it for your surface or another coating. UK prices cover a small Wickes sample; US records contain manufacturer specifications, with prices entered by you.

Product specifications and source links; no reviews or suitability rankings
Recorded product	Coverage per coat	Recorded coats	Container sizes	Price	Source
Dulux Matt Emulsion Paint - Pure Brilliant White - 2.5L	13 m²/L	Confirm on label	2.5 L	£22.00 · recorded 2026-10-13	Wickes ↗
Dulux Matt Emulsion Paint - Pure Brilliant White - 5L	13 m²/L	Confirm on label	5 L	£26.00 · recorded 2026-10-13	Wickes ↗
Dulux Easycare Washable & Tough Matt Emulsion Paint - Pure Brilliant White - 2.5L	13 m²/L	Confirm on label	2.5 L	£27.00 · recorded 2026-10-13	Wickes ↗
Dulux Easycare Washable & Tough Matt Emulsion Paint - Pure Brilliant White - 5L	13 m²/L	Confirm on label	5 L	£38.00 · recorded 2026-10-13	Wickes ↗
Dulux Easycare Bathroom Soft Sheen Emulsion Paint - Pure Brilliant White - 2.5L	13 m²/L	Confirm on label	2.5 L	£27.00 · recorded 2026-10-13	Wickes ↗
Wickes Matt Emulsion Paint - Pure Brilliant White NO.0 - 2.5L	13 m²/L	Confirm on label	2.5 L	£13.00 · recorded 2026-10-13	Wickes ↗
Zinsser Bulls Eye 123 Primer Sealer - White - 2.5L	10 m²/L	Confirm on label	2.5 L	£38.00 · recorded 2026-10-13	Wickes ↗