Paint Calculator

What this means

Paint needed depends on the wall area, how many coats you apply, and the paint's spread rate. We total the four walls, subtract a typical area for each door and window, multiply by your coats, and divide by a standard coverage rate. Always round up — running out mid-wall means a visible lap mark.

Recommendations

• •Buy a little extra for touch-ups later, and keep the batch number in case you need to colour-match.
• •Porous, textured or dark-to-light surfaces soak up more paint — add 10–15% for those.
• •A primer coat is worth it on new plaster or big colour changes, and it improves final coverage.

Watch out

• •Coverage rates vary by brand and surface — check the tin, which is the authority for that specific paint.