Paint Calculator
Calculate how many litres of paint you need to cover walls, ceilings, or a room. Accounts for doors, windows, coats, and paint coverage rate.
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How to use this calculator
Net area = total wall area minus doors and windows. Coverage rate is typically 10–14 m² per litre for standard interior paint.
- 1
Enter the room dimensions and ceiling height.
- 2
Enter the number of doors and windows to subtract from paintable area.
- 3
Set the number of coats (2 is standard for good coverage) and your paint's coverage rate (check the tin — typically 10–14 m²/L).
Frequently asked questions
How much does one litre of paint cover?
Standard interior emulsion typically covers 10–14 m² per litre per coat on a smooth surface. Rough or porous surfaces absorb more paint and reduce coverage to 8–10 m²/L. Always check the product specification on the tin.
How many coats of paint do I need?
Two coats are standard for most interior repaints. If changing from a dark to a light colour, or painting new plaster, three coats may be needed. Primer + 2 topcoats is the professional standard for new surfaces.
Should I buy extra paint?
Yes — add 10–15% to allow for touch-ups, uneven application, and future repairs. Also, identical paint mixed later may not match perfectly, so buy your full requirement in one batch.
Paint Calculator — Litres Needed for Walls & Ceilings
Types of interior paint
Matt/flat: hides surface imperfections, not washable — use on ceilings and feature walls. Eggshell/satin: slight sheen, more durable and washable — ideal for living rooms and bedrooms. Semi-gloss/gloss: highly durable and washable — best for kitchens, bathrooms, and trim.
Tips for a professional finish
Clean and repair surfaces before painting. Use painter's tape for crisp edges. Apply paint in a "W" pattern with a roller, then fill in without lifting the roller. Cut in edges with a brush first. Apply the second coat only after the first is fully dry (check the tin for recoat time — typically 2–4 hours).
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →