Exterior Paint Calculator
An exterior paint calculator finds how much paint your home's exterior needs by calculating the wall area of the siding, subtracting doors and windows, and dividing by gallon coverage for your coats. Exterior and textured surfaces often need more paint, so coverage runs lower. Enter your dimensions below.
Use lower coverage (~300 sq ft/gal) hint for rough siding; coats default 2.
- 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 Much Exterior Paint Do You Need?
To calculate exterior paint, add the length of all exterior walls, multiply by height for total area, subtract doors and windows, then divide by coverage and multiply by coats. Exterior surfaces like rough siding and stucco absorb more, so coverage can drop to around 300 square feet per gallon instead of 350. A two-story home can need 6 to 10 gallons for two coats. The calculator lets you set coverage and coats for accuracy.
Why Does Exterior Paint Cover Less?
Exterior paint covers less because exterior surfaces are usually rougher and more porous than interior drywall: lap siding, stucco, brick and weathered wood all have more surface area and soak up paint. This is why exterior estimates use a lower coverage figure. Always add a margin for these surfaces, which the calculator allows by adjusting the coverage rate.
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Frequently asked questions
- How much exterior paint for a house?
- It depends on size, but a two-story home often needs 6 to 10 gallons for two coats. Rough siding lowers coverage, so calculate from your wall area and surface type.
- Why does exterior paint cover less than interior?
- Exterior surfaces like siding, stucco and brick are rougher and more porous, so they absorb more paint, dropping coverage from about 350 to around 300 square feet per gallon.