Paint Calculator - Estimate Paint Gallons Needed for Any Room

How to Use the Paint Calculator

1. Enter room dimensions — length, width, and height
2. Subtract openings — number of windows and doors
3. Choose coats — 1 or 2 coats
4. Get gallons — exact paint needed for walls, ceiling, and trim

Perfect for homeowners, painters, and contractors planning interior painting projects. All calculations are done in your browser.

Features

• Walls, ceiling, and trim — separate estimates for each
• Door/window subtraction — subtracts standard sizes
• Multiple coats — automatically doubles for 2 coats
• Gallon precision — rounds up to nearest gallon
• Waste allowance — includes 10% buffer