How to measure walls for paint
Measuring paint starts with the area you intend to coat, not the floor area of the room.
Measure each wall or use the room perimeter
For a simple room, multiply the wall perimeter by wall height. For one wall, multiply its width by height. Keep ceilings, trim, doors, and special surfaces as separate estimates when they use a different product or number of coats.
Paintable wall area
wall perimeter × height − large opening areaExample: a 14 m perimeter at 2.4 m high is 33.6 m². Deducting 1.8 m² of openings leaves 31.8 m² to coat.
Deduct openings deliberately
Large doors, windows, and unpainted sections can be deducted as combined area. Small reveals, trims, repair patches, and cut-in work may counterbalance small deductions, so do not subtract every tiny feature automatically.
Multiply by coats
Two coats double the coating area. In the example above, 31.8 m² becomes 63.6 m² of coated area for two coats before the label coverage is applied.