Why Getting the Right Amount of Paint Matters
Buying too little paint can delay your project, while buying too much wastes money. A simple calculation helps you get it right the first time.
Standard Paint Coverage in Australia
On average:
- 1 litre of paint covers 10 to 12 square metres per coat
- Most surfaces require 2 coats
Step 1: Measure Your Room
To calculate wall area:
Wall area = height × width
Example:
- Wall height: 2.4m
- Wall width: 5m
- Area = 12m²
Repeat for all walls and add them together.
Step 2: Subtract Doors and Windows
- Standard door ≈ 2m²
- Standard window ≈ 1.5m²
Subtract these from your total wall area.
Step 3: Multiply by Number of Coats
Most paint jobs require 2 coats for proper coverage.
Step 4: Divide by Coverage Rate
Formula:
Total litres needed = Total area ÷ coverage per litre
Example Calculation
Room size:
- Total wall area: 40m²
- 2 coats needed
- Coverage: 10m² per litre
Total paint needed:
40 × 2 ÷ 10 = 8 litres
Room by Room Paint Guide
Bedroom
- Average size: 30–40m² wall area
- Paint needed: 6–8 litres
Living Room
- Larger space: 50–70m²
- Paint needed: 10–14 litres
Kitchen
- Smaller wall space due to cabinets
- Paint needed: 4–6 litres
Ceiling
- Area = length × width
- Usually requires 1–2 coats
Pro Tips to Avoid Running Short
- Always add 10% extra for wastage
- Rough or textured walls use more paint
- Dark colour changes may need 3 coats
- New surfaces need a primer first
Final Verdict
A simple calculation can save you both time and money. Always measure carefully, account for coats, and buy a little extra to avoid interruptions during your project.