Paint & Wallpaper Coverage Calculator
Enter your room dimensions, number of doors and windows, and whether you're using paint or patterned wallpaper to get an accurate material estimate including waste.
Material needed
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Net wall area (sq ft)—
Deducted for doors/windows (sq ft)—
Coats applied / Waste multiplier—
Total needed (gallons or rolls)—
About this calculator
Calculate how much paint or wallpaper you need across multiple rooms, accounting for door/window deductions and pattern-repeat waste.
Frequently Asked Questions
How much paint covers a wall?
One gallon of paint typically covers about 350 square feet with a single coat, though this varies by paint brand and wall texture.
Why does pattern repeat increase wallpaper waste?
Patterned wallpaper needs to be aligned across strips, which means extra material is cut and wasted to match the repeat, especially with large or complex patterns.
How much area does a standard door or window take up?
This calculator assumes about 20 square feet for a standard door and 15 square feet for a standard window, which are typical averages.