Paint Square Footage Calculator
A paint square footage calculator finds your paintable area in square feet and converts it to gallons of paint. It adds wall area, subtracts doors and windows, and divides by coverage for your coats. Enter your wall dimensions below to get both the square footage and the gallons.
- Paintable area
- 0 sq ft
- Coats
- 2
Enter your dimensions to see the gallons you need.
Estimate only. Material yields vary by product and brand; check your product label and add a margin.
How Do You Calculate Paint Square Footage?
To calculate paint square footage, multiply the total length of your walls by their height for the gross wall area, then subtract about 21 square feet per door and 15 per window. The result is the paintable square footage. Dividing it by the coverage per gallon and multiplying by coats gives the gallons. Knowing the square footage first makes it easy to compare paint products by their stated coverage.
Why Start From Square Footage?
Square footage is the base figure every paint estimate depends on, because coverage is always quoted per square foot or per gallon over a square-foot area. Once you have an accurate paintable square footage, you can plug in any product's coverage rate to get its gallon count. This calculator gives you that square footage explicitly, alongside the gallons for a standard coverage.
Related calculators
Frequently asked questions
- How do I calculate square footage for paint?
- Multiply total wall length by height, then subtract about 21 square feet per door and 15 per window. The result is your paintable square footage.
- How many square feet does a gallon of paint cover?
- About 350 square feet per coat on smooth primed surfaces, less on textured or porous walls. Use your product's stated rate for the gallon count.