About Wall & Ceiling Paint Calculator
Determine exact paint gallons, quarts, and primer needed for interior rooms and exteriors. Automatically subtracts doors and windows, supports smooth vs textured drywall, and multi-coat applications.
Key Capabilities & Features
- Room perimeter and ceiling height area computation
- Automatic deductions for doors (21 sq ft) and windows (15 sq ft)
- Optional ceiling paint area calculation
- Texture calibration: Smooth (350-400 sq ft/gal), Textured (300), Rough (250)
- Gallons, quarts, liters, and separate primer coat estimation
How to Use Wall & Ceiling Paint Calculator
Enter Room Measurements
Provide length, width, and wall height in feet.
Count Openings
Input door and window counts to subtract unpainted areas.
Select Coats & Surface
Choose 2 coats standard and select whether to include ceiling paint.
Get Paint Order
Review total gallons and quarts to purchase at the paint store.
Privacy & In-Browser Execution Guarantee
100% client-side calculation. Your project measurements never leave your device.
Frequently Asked Questions
How many square feet does one gallon of paint cover?
One gallon of quality interior paint covers approximately 350 to 400 square feet of smooth drywall with a single coat. Textured walls reduce coverage to 250-300 sq ft.
Do I really need two coats of paint?
Yes, two coats provide uniform color saturation, hide underlying wall imperfections, and significantly improve washability and durability.