Calculators / Paint
Paint Calculator
To calculate paint, enter the total wall length, height, and number of coats; this tool returns the gallons needed and a cost estimate. One gallon covers about 350 square feet per coat.
Real math, not AI guesses.
You need
2 gallons
Estimated cost
~$70
- Wall area
- 320 sq ft
- Coats
- 2
- Gallons (350 sq ft/coat)
- 2
Estimate only — actual quantities and prices vary by region and supplier. Verify with a professional before purchasing. Default price is a national average (as of 2026-06); edit it to match your supplier.
How to calculate paint
The formula: gallons = ceil( wall area × coats ÷ 350 )
- Add up the length of all walls and multiply by the wall height for total area.
- Subtract large openings like doors and windows if you want a tighter estimate.
- Multiply area by the number of coats.
- Divide by 350 (coverage of one gallon) and round up.
Prices shown are national averages (as of 2026-06) and vary by region, brand, and supplier. They are estimates, not quotes.
Paint FAQ
How much paint do I need for a room?+
A room with 40 ft of wall at 8 ft high is 320 sq ft. For two coats that is 640 sq ft, or about 2 gallons at 350 sq ft per gallon.
Does one gallon of paint do two coats?+
One gallon covers about 350 sq ft for a single coat. For two coats, plan on roughly one gallon per 175 sq ft of wall.