Exterior Paint Calculator
Estimate exterior paint for wood siding, stucco, masonry, or textured surfaces by area, surface type, and coats.
Formula & Explanation
Exterior paint coverage depends on surface texture and material. This calculator uses the formula: Gallons = (Wall area × Number of coats) ÷ Coverage per gallon Example (smooth siding): 800 sqft × 1 coat ÷ 350 sqft/gallon ≈ 2.3 gallons → purchase 3 cans or 1 five-gallon bucket. The key difference from interior is that exterior surfaces (wood, stucco, masonry) are often more porous, requiring lower coverage rates and thus more paint.
Assumptions
- •Smooth wood siding: 300-400 sqft/gallon coverage (varies by wood type and weathering)
- •Textured siding or cedar: 250-350 sqft/gallon (rougher = more absorption)
- •Stucco or masonry: 200-300 sqft/gallon (highly porous)
- •Exterior latex paint is weather-resistant; always check product specifications
- •Two coats are recommended for new construction or dramatic color changes; one coat for refresh if surface is well-sealed
- •Primer may be needed on bare wood or stucco; use primer-calculator for primer estimates
- •Assumes normal temperature and humidity during application (50-85°F, <85% humidity)
- •Exterior paint typically costs more than interior due to additives for UV and weather resistance
- •Trim, fascia, and soffits are calculated separately
Example Calculation
800 square feet of smooth exterior siding with one coat at 350 sqft/gallon coverage requires 2.29 gallons. Purchase 3 gallon cans or 1 five-gallon bucket.
Inputs
Results
Exterior Paint Coverage by Surface
| surface | coverage | notes |
|---|---|---|
| Smooth wood siding | 300-400 sqft/gal | Well-maintained or pre-primed |
| Rough/weathered wood | 250-300 sqft/gal | Porous, absorbs more paint |
| Cedar or redwood | 250-350 sqft/gal | Naturally porous; prime if bare |
| Stucco | 200-300 sqft/gal | Very porous; multiple coats may be needed |
| Masonry/concrete | 200-250 sqft/gal | Use masonry-specific paint |
| Exterior primer | 250-350 sqft/gal | Often lower coverage than topcoat |
Frequently Asked Questions
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