House Paint Calculator
घर रंग क्याल्कुलेटर
Estimate the paint required for walls and ceilings from room dimensions, coats and coverage.
Estimate the paint you need for walls and ceilings. Enter the room size, subtract doors and windows, choose your coats and coverage, and the calculator returns the paintable area, litres of paint and an optional cost.
- Wall area
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- Ceiling area
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- Gross area
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- Net paintable area
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- Paint per coat
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- Total paint to buy
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- Estimated paint cost
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About the house paint calculator
This calculator estimates how much paint you need to redecorate a room or a whole house. Enter the room size and wall height, add the ceiling if you are painting it, subtract the area taken by doors and windows, and choose the number of coats. The tool gives you the paintable area, the paint required in litres and an optional cost estimate.
How paint quantity is worked out
The wall area of a room is its perimeter (2 × (length + width)) multiplied by the wall height. Add the ceiling area if you are painting it, then deduct the area of doors and windows, which do not need paint. Divide the remaining area by the paint's coverage to get the litres for one coat, then multiply by the number of coats.
Coverage varies — check your tin
Coverage is the area one litre covers in a single coat. For interior emulsion it is usually around 110–150 sq ft per litre on a normal masonry surface, and it rises on a previously painted wall because the surface is less porous. The figure is printed on the tin, so enter that value for the best estimate. Two coats are standard for a rich, even finish.
Primer, putty and wastage
Paint is only part of a repaint. New or patchy plaster usually needs a wall putty and a primer coat before the emulsion, and both are estimated separately. Keep a wastage allowance of about 5–10% for touch-ups, roller loss and the last half-litre you cannot pour out — it is cheaper than a second trip to the shop.