Paint coverage: walls, ceiling, doors/windows
Wall area 2×(L+W)×H minus doors 1.9m² and windows 1.5m². Divide by coverage m²/L, times coats, ceil to cans. One coat rarely enough.
TL;DR
- Perimeter×height = wall, subtract openings, net / coverage per coat, × coats, round up to 1L/5L
- Formulas: Wall=2(L+W)×H | Net=Wall-Doors1.9-Windows1.5 | Liters=Net/Coverage×Coats
- 4×5 H2.7
How it works
Perimeter×height = wall, subtract openings, net / coverage per coat, × coats, round up to 1L/5L. 45.2m² 10m²/L 2 coats →9L.
The math
4×5 H2.7 1door1window: wall48.6 net45.2 2 coats 9L →2×5L. 3×3 H2.5 no openings 1 coat 12m²/L →2.5L→3×1L.
Ceil because cannot buy fractional can. Add 10% rough walls.
Examples
4×5 H2.7
- Net 45.2
- 9L
3×3 H2.5
- 2.5L →3L
When to use it
✦ Renovation
Buy correct cans.
✦ Quotes
Painter estimates.
⚠ Common mistakes
- Not subtracting doors/windows
- Single coat when need two
FAQ (6)
What coverage to use?
Check can: typical 10-14 m²/L for walls. Rough walls use lower.
Ceiling included?
Not by default. Add ceiling area L×W if painting it.
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