Construction Tool
Paint Coverage Calculator
Estimate how much paint you need for your next room makeover. Just input the dimensions of your room, the number of doors and windows, and we'll calculate the footprint in gallons or liters.
How do you calculate paint coverage?
Calculating paint coverage is easy once you know your wall dimensions. Our calculator performs the standard "Room Perimeter" calculation automatically:
- 1. Find Total Wall Area: (Room Length + Room Width) × 2 × Ceiling Height
- 2. Deduct Obstacles: Subtract ~21 sq ft (2 sq m) per door and ~15 sq ft (1.4 sq m) per window.
- 3. Find Total Paint Need: Divide the final footage by your paint's spread rate (typically 350 sq ft per gallon or 10 sq m per liter).
How many coats of paint do I need?
Most interior projects require at least two coats for a durable, true-to-color finish.
- 1 Coat: Only suitable when re-painting the exact same color over a clean wall with high-quality paint.
- 2 Coats: The industry standard. Delivers rich color and covers minor underlying imperfections.
- 3+ Coats: Necessary when painting over a dark color with a lighter color, or when painting over porous fresh drywall (if not using a separate primer).
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