To calculate the amount of paint required for a surface, follow these steps:

1. Measure the Surface Area

• For walls: Multiply the height by the width of each wall.

• For ceilings/floors: Multiply the length by the width.

• If there are doors or windows, subtract their areas.

Formula:

Total Surface Area= (Height×Width)−(Doors/Windows Area)

2. Determine Paint Coverage

• Check the paint can for coverage information (usually in square meters or square feet per liter/gallon).

• Standard coverage is 10-12 m² per liter (or 350-400 sq ft per gallon) for a single coat.

3. Calculate Paint Required

Paint Required = Total Surface Area / Paint Coverage per Liter/Gallon

• If multiple coats are needed, multiply by the number of coats.

Example Calculation

Wall Painting

• Room: 4 walls, each 3m height × 5m width

• Total area: (3 × 5) × 4 = 60 m²

• Doors & windows area: 6 m²

• Net area: 60 – 6 = 54 m²

• Paint coverage: 10 m² per liter

• Paint needed: 54 ÷ 10 = 5.4 liters

• For 2 coats: 5.4 × 2 = 10.8 liters