Coverage is usually written as square metres per litre or square feet per gallon. It describes the area a paint can cover under stated conditions, typically for one coat on a prepared surface. It is not a guarantee for every wall.
| Label unit | Useful comparison |
|---|---|
| 1 m² per litre | About 40.9 sq ft per gallon |
| 10 m² per litre | About 409 sq ft per gallon |
| 350 sq ft per gallon | About 8.6 m² per litre |
What reduces coverage?
New plaster, bare drywall, repaired filler, textured walls and dark-to-light changes can all use more paint. Rough exterior render and weathered timber can use substantially more than a smooth sealed wall. Applying too thickly can also create problems; the answer is not simply to load on more paint.
Water-based and oil-based paints
Both can vary widely by product. Water-based wall paints often have clear coverage figures and are common for interior walls. Oil- or alkyd-based paints may be chosen for specific trims or durability needs, but their coverage, drying and application requirements are product-specific. Compare the exact label, not just the paint base.
Use the right planning buffer
For a clean, previously painted wall, a modest 10% allowance is often practical. Increase the allowance when surfaces are porous, patterned, repaired or difficult to access. Keep leftover paint in a sealed, labelled container for touch-ups.
Use the coverage converter when a paint label uses a different unit from your project measurements.