How to estimate paint for your house exterior
Exterior siding is thirstier than smooth interior drywall, so this calculator defaults to 300 square feet per gallon. Enter the footprint length, width, and wall height of your house, and it estimates the paintable surface after doors and windows.
For a two-story home, use the full wall height (roughly 9 feet per story plus the gable). Rough stucco, cedar shake, or bare wood can drop coverage to 250 or less, so adjust coverage in Advanced for the toughest surfaces.
Coverage cheat sheet
| Surface / situation | Approx. coverage per gallon |
|---|
| Smooth, previously painted surface | 350 to 400 sq ft |
| New or bare wood / drywall (thirsty) | 250 to 350 sq ft |
| Textured, rough, or weathered | 200 to 300 sq ft |
| Primer | 200 to 300 sq ft |
This tool defaults to 300 sq ft per gallon for a house exterior. Change it under
Advanced if your surface is rougher or more porous than average.
Frequently asked questions
How much paint do I need to paint a house exterior?
A typical single-story 1,500 sq ft house needs about 6 to 10 gallons for two coats, depending on how many windows and doors it has and how rough the siding is. Enter your actual dimensions above for a specific number.
Why does exterior paint cover less than interior paint?
Exterior surfaces like lap siding, stucco, and cedar are more textured and porous than interior drywall, so a gallon spreads over less area. Using 300 sq ft per gallon (or less for rough surfaces) keeps your estimate realistic.
How many square feet does a gallon of paint cover?
One gallon of interior wall paint typically covers 350 to 400 square feet in a single coat. Textured, porous, or dark-to-light surfaces cover less, so this calculator uses a conservative default to keep you from coming up short.
Should I buy extra paint?
Yes. Keep a little for touch-ups. Rounding up to full gallons usually gives you enough of a cushion; for large jobs, add roughly 10 percent so you have a color-matched can on the shelf later.