Exterior Paint Calculator — How Much Paint for a House?
Enter your house wall area, openings and trim to get siding and trim paint in gallons for one or two coats. No sign-up, no data stored.
Exterior paint needed
How exterior paint is estimated
- Wall area (sq ft) = house perimeter x wall height.
- Siding area = wall area - windows and doors.
- Siding gallons = siding area x coats ÷ coverage (350 or 250 sq ft/gal).
- Trim gallons = trim linear ft x 0.33 (about 4-in average width) x coats ÷ 250.
- Total = siding + trim gallons, rounded up to buying units.
Perimeter x height misses gables and dormers - for a house with big gables, add the gable area (base x height ÷ 2) per gable before subtracting openings.
House size → exterior paint reference
One coat, smooth siding at 350 sq ft/gal, 200 ft of trim.
| House | Wall area | After openings | Siding | Trim |
|---|---|---|---|---|
| 1,000 sq ft ranch | 1,200 sq ft | 900 sq ft | 3 gal | 1 gal |
| 1,500 sq ft ranch | 1,500 sq ft | 1,100 sq ft | 4 gal | 1 gal |
| 2,000 sq ft two-story | 2,200 sq ft | 1,700 sq ft | 5 gal | 2 gal |
| 2,500 sq ft two-story | 2,600 sq ft | 2,000 sq ft | 6 gal | 2 gal |
Last updated: October 2026 · Coverage drops on rough surfaces and in cold weather. Buy a quart extra for touch-ups after the season settles.
Exterior paint FAQ
A typical 1,500-sq-ft one-story house has about 1,500-2,000 sq ft of siding - after windows and doors, roughly 1,500 sq ft - so one coat needs about 5-6 gallons. Two coats double that, plus trim.
Yes - soffits and fascia are usually a different color and can add 200-400 sq ft on a ranch home. Measure eave length x soffit width for soffits, and linear feet x width for fascia, then add to trim.
Vinyl and smooth wood take about 350-400 sq ft per gallon; rough stucco and cedar shingles soak up more - 250-300 sq ft per gallon. Our calculator has coverage presets for both.
Two coats for new or bare wood, or when changing color by more than two shades. A quality one-coat repaint in the same color family is acceptable on sound siding - but always prime bare spots first.
Paint between 50-85°F, out of direct sun, and when rain is not forecast for 24 hours. Latex paint applied below 50°F forms poor film; above 85°F it dries too fast and lap marks show.
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How Much Exterior Paint Do I Need?
House math, coverage by siding and the trim trap most people miss.
Read the guide →