Paint Coverage Calculator
Calculate how much area a given amount of paint will cover based on paint type and surface
Paint on Hand
Area to Paint
Paint & Surface Settings
Check the manufacturer's label for coverage per gallon
Results
Step-by-Step Calculation
Understanding Paint Coverage
Paint coverage (also called spread rate) is the area that one gallon of paint will cover in a single coat. This rate is printed on every paint can and varies based on paint type, quality, and finish. Real-world coverage depends heavily on the surface texture, application method, and how thickly the paint is applied.
Key Formulas:
Coverable Area = Paint Volume × Spread Rate ÷ Number of Coats
Paint Needed = (Area × Number of Coats) ÷ Adjusted Spread Rate
Adjusted Rate = Base Rate × Surface Factor
Paint Spread Rate Reference
| Paint Type | Coverage (ft²/gal) | Coverage (m²/L) | Notes |
|---|---|---|---|
| Interior Flat / Matte | 350-400 | 8.6-9.8 | Best coverage, hides imperfections |
| Interior Eggshell / Satin | 350-400 | 8.6-9.8 | Most popular wall finish |
| Interior Semi-Gloss | 350-400 | 8.6-9.8 | Trim, doors, kitchens, bathrooms |
| Interior High Gloss | 300-350 | 7.4-8.6 | Cabinets, accent trim, furniture |
| Exterior Flat / Satin | 250-350 | 6.1-8.6 | Lower coverage due to surface texture |
| Primer / Sealer | 250-350 | 6.1-8.6 | Seals porous surfaces, required for new drywall |
| Stain (wood) | 200-350 | 4.9-8.6 | Varies widely by wood porosity and stain type |
How Surface Type Affects Coverage
Rough and porous surfaces absorb more paint and have more surface area per square foot, reducing effective coverage. Smooth surfaces allow paint to spread further.
Smooth Surfaces
100% of rated coverage
- • Smooth drywall
- • Plaster
- • Previously painted surfaces
- • Sanded wood
Textured Surfaces
~85% of rated coverage
- • Orange peel texture
- • Knockdown texture
- • Light stucco
- • Textured ceilings
Rough / Porous Surfaces
~65-75% of rated coverage
- • Heavy stucco
- • Brick / block
- • Unfinished concrete
- • Rough-sawn wood
Color Change & Coating Recommendations
| Scenario | Recommended Coats | Primer Needed? | Notes |
|---|---|---|---|
| Same / similar color | 1-2 | No | Touch-ups may need only 1 coat |
| Light to dark | 2 | Optional (tinted primer helps) | Tinted primer reduces coats needed |
| Dark to light | 2-3 | Yes | White primer essential to block dark color |
| New / unpainted surface | 1 primer + 2 | Yes | Primer seals and provides uniform base |
Tips for Maximizing Paint Coverage
- Use a high-quality roller cover — thicker nap (3/4") for textured surfaces, thinner (3/8") for smooth walls
- Apply paint at the manufacturer's recommended thickness — too thin wastes coverage, too thick causes drips
- Maintain a "wet edge" by overlapping each roller pass before it dries
- Prime porous or stained surfaces to prevent the topcoat from soaking in
- Tint your primer toward the topcoat color for better coverage with fewer coats
- Stir paint thoroughly before use — settled pigments reduce coverage and color accuracy
- Avoid painting in extreme temperatures; ideal range is 50-85°F (10-29°C)
- Use a brush for edges and corners, and a roller for large flat areas
- Back-roll after spraying to ensure even coverage and eliminate thin spots
Related Calculators
Note: Paint coverage varies by brand, color, and application method. Dark and vivid colors (reds, yellows, deep blues) typically require more coats than neutral colors. Always check the manufacturer's stated coverage on the paint label and test a small area first.
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