Wall Paint Coverage Calculator Pro (USA)
Accurately estimate gallons of paint needed for your interior rooms. Designed for US measurements (Feet/Inches).
Room Dimensions
🚪 Exclude Non-Painted Areas
Subtracts ~21 sq. ft per door
Subtracts ~15 sq. ft per window
How to Calculate Wall Paint Coverage (USA Guide)
Painting a room requires accurate planning to avoid multiple trips to the hardware store. This Wall Paint Coverage Calculator Pro (USA) is designed to simplify the process for American homeowners using standard Imperial units.
📏 The Standard Formula
To calculate manually, use this formula:
- Wall Area: (Length + Width) × 2 × Height
- Subtract Openings: Subtract approx. 21 sq. ft. per door and 15 sq. ft. per window.
- Total Coverage: Multiply the final area by the number of coats (usually 2).
🖌️ How Much Does 1 Gallon Cover?
Typically, one gallon of standard interior latex paint covers about 350 to 400 square feet with a single coat. However, this varies based on surface texture:
- Smooth Walls: Up to 400 sq. ft.
- Textured/Rough Walls: May only cover 250-300 sq. ft.
Why Include 10% Extra?
Our calculator automatically adds a 10% buffer for spillage, touch-ups, and variations in surface absorption. It is always better to have a quart left over than to run out of paint halfway through a job.
