Exterior Paint Calculator
Body and trim gallons, sized for your siding. Free, instant, and private — everything runs on your device.
Footprint, not lot
250–350; lower for rough siding
Your exterior paint estimate
- Wall area (after openings & texture)
- 1,068 sq ft
- Body paint
- 8 gal
- Trim paint (2 coats)
- 1 gal
- Estimated cost
- $432
Exterior coverage runs lower than interior, and rough or porous siding drinks even more — the texture setting accounts for that. Body and trim are usually different paints (and sheens), so they're estimated separately. Paint in mild, dry weather.
Estimating exterior paint the way you'd estimate a bedroom leaves you short every time. Outdoor coverage runs lower than indoor, rough or porous siding drinks far more than a smooth wall, and the trim is a separate product in a separate sheen that never gets counted. This calculator handles all three. Enter your home's footprint and number of stories, choose your siding texture, and it works out the body gallons and the trim gallons separately, with a cost.
It converts your footprint into wall area, applies a texture factor so stucco and cedar shake don't come up short, subtracts your doors and windows, and adds the coats you plan to apply. The result is the number of gallons to carry to the register — so a two-weekend job doesn't turn into three because of a mid-project paint run.
How it works
No black box — this is the exact math the calculator runs.
- Wall area = perimeter (2 × [length + width]) × (stories × ~9 ft) × a siding-texture factor.
- Texture factor: smooth lap/vinyl ×1.0, textured T1-11/cedar ×1.3, stucco/masonry ×1.5.
- Subtract 21 sq ft per door and 15 sq ft per window.
- Body gallons = (wall area × coats) ÷ coverage (250–350 sq ft/gal outdoors).
- Trim is estimated at about 12% of body area over two coats, as a separate product; cost = total gallons × your price.
Last reviewed July 24, 2026 · Paint & Decor
Frequently asked questions
How much exterior paint do I need for a 2,000 square foot house?
For a typical single-story home with about a 1,000 sq ft footprint (roughly a 40×30 shape), two coats on smooth siding runs around 8 gallons of body paint plus 1–2 gallons of trim. Two stories, rough siding, or a bigger footprint pushes that higher — enter your real numbers for an accurate count.
Why does exterior paint cover less than interior paint?
Exterior surfaces are rougher and more porous, and they've weathered — chalky, sun-baked, or previously unpainted siding absorbs more. Textured products like stucco and cedar shake have far more actual surface than their flat dimensions suggest, which is why the calculator applies a texture factor.
Should I paint the body and trim with the same paint?
Usually no. Body paint is typically a flat or satin, while trim, doors, and fascia get a more durable, higher-sheen paint that stands up to handling and weather. Because they're different products, this calculator estimates their gallons separately.
How many coats does exterior paint need?
Two coats is standard for durability and even coverage, especially over a color change or bare/repaired siding. A single coat may work when repainting the same color over sound, previously painted surfaces — but two coats is what gets the full warranty life.