What a paint can really covers.
A coverage figure is a product-specific input, not a universal property of paint. Dulux’s calculator notes that coverage varies with the surface and product. Start with the label for the exact finish you plan to buy.
Separate surface area from coat area
A room with 30 m² of paintable wall still has 30 m² of wall when you apply two coats. But you must cover it twice: 60 m² of coat area. At an entered coverage of 10 m²/L, that means 6 L before your allowance. Those figures illustrate the arithmetic; they are not a product recommendation.
Then decide on an allowance
Coverage estimates cannot fully describe a porous, textured or previously repaired wall. Use an allowance deliberately and follow the preparation instructions for your product. In our example, 10% adds 0.6 L. With 2.5 L cans, 6.6 L requires three cans, giving 7.5 L in total.
Keep different finishes separate
Ceilings, trim and walls may need different products. Calculate each separately rather than using one coverage value for all of them. Primer also deserves its own line if specified. Label saved project entries so your shopping list distinguishes wall paint from ceiling paint.
Before you place the order
Confirm the intended number of coats, container size and coverage basis. Some coverage descriptions refer to a complete system rather than one coat. Our calculator expects coverage per coat. A lower entered coverage increases the calculated requirement.
Source: Dulux Paint Calculator, consulted 9 November 2026. Project arithmetic is independently calculated.