KNOW THE MATH
How it works
Estimate paint for four walls of a rectangular room. Subtract combined door and window area, select coat count and use the coverage rate on the product label. Ceilings are excluded.
Formula
Liters = ([2 × (length + width) × wall height] − openings) × coats ÷ coverage × (1 + waste percentage).
Worked example
A 5 × 4 × 2.5 m room has 45 m² of wall area before removing openings.