🎨 Wall Paint Calculator

Estimate exactly how much paint and budget you'll need

Paint Required
—
Total Wall Area
—
Estimated Paint Cost
—

Wall Paint Calculator — How Much Paint Do You Need?

Buying the right amount of paint avoids both an incomplete job (running short mid-project, mismatched batches) and wasted money on excess unused paint. This calculator estimates paint quantity based on standard industry coverage rates.

Standard Coverage Assumption

This calculator assumes 1 litre of paint covers approximately 120 sq.ft per coat — a typical figure for emulsion paints on previously painted, smooth walls. Textured walls, new plaster (which absorbs more paint), or budget paints may have lower coverage.

Why Most Rooms Need 2 Coats

A single coat rarely gives uniform, opaque color coverage, especially over a different existing color or new plaster. Two coats is the standard recommendation for most residential painting jobs; three coats may be needed for dramatic color changes (e.g., dark to light).

Frequently Asked Questions

Does this account for doors and windows? +
No — this calculator uses gross wall area without subtracting door/window openings, which provides a small safety buffer. For very large window walls, you can manually reduce the area estimate by the opening size.
Why might my actual paint usage differ from this estimate? +
Coverage varies by paint brand and quality, wall texture (rough/textured walls absorb more paint), surface porosity (new plaster vs previously painted), and application method (roller vs spray vs brush).
Should I buy primer separately? +
Yes — primer is a separate product and not included in this estimate. New walls or significant color changes typically need a coat of primer before the topcoat paint, which has its own coverage rate and cost.