How Much Paint Coverage Should You Expect?

What the can's coverage figure represents

Paint manufacturers state an expected coverage rate (commonly in the range of 250-400 square feet per gallon, varying by product) based on testing under fairly controlled, ideal conditions — a smooth, properly-prepared surface with standard application. It's a reasonable planning figure, but it's not a guarantee for every real-world surface.

What causes coverage to vary

• Surface texture — a heavily textured wall absorbs more paint per square foot than a smooth one
• Porosity — bare drywall, unprimed wood, or masonry soak up more paint than a previously painted, sealed surface
• Color change — going from a dark existing color to a much lighter new color (or vice versa) often needs an extra coat regardless of the stated coverage rate
• Application method — spraying, rolling and brushing all deposit paint at somewhat different rates and with different overspray/waste characteristics

Planning around the uncertainty

Use the can's coverage figure as your starting estimate, but buy from a supplier that allows returns of unopened cans where possible, and consider a small buffer for a textured, porous, or dramatically color-shifted surface rather than cutting the order exactly to the calculated minimum.