You typically need about 0.0025 to 0.0029 gallons of paint per square foot for one coat. Put more simply, one gallon of paint generally covers around 350 to 400 square feet of a smooth surface.
For two coats, you need roughly twice as much paint. For example, 1,000 square feet of paintable surface would typically require about 5 to 6 gallons for two coats.
Actual coverage varies depending on the specific paint, surface condition, texture, application method, and other factors, so always check the coverage listed for the paint you’re using.
How to Calculate Gallons of Paint by Square Foot
To estimate how many gallons you need, use this simple formula: Square footage ÷ coverage per gallon × number of coats = gallons of paint needed
For example, if you’re painting 1,000 square feet and your paint covers 400 square feet per gallon: 1,000 ÷ 400 × 2 coats = 5 gallons
If the same paint covered 350 square feet per gallon, you would need approximately 5.7 gallons for two coats.
How Much Paint Do You Need for Different Square Footages?
Using an estimated coverage rate of 350 to 400 square feet per gallon, here’s approximately how much paint different surface areas require:
| Paintable Area | 1 Coat | 2 Coats |
|---|---|---|
| 100 sq. ft. | 0.25–0.3 gal. | 0.5–0.6 gal. |
| 250 sq. ft. | 0.6–0.7 gal. | 1.25–1.5 gal. |
| 500 sq. ft. | 1.25–1.5 gal. | 2.5–3 gal. |
| 1,000 sq. ft. | 2.5–3 gal. | 5–6 gal. |
| 1,500 sq. ft. | 3.75–4.3 gal. | 7.5–8.6 gal. |
| 2,000 sq. ft. | 5–5.7 gal. | 10–11.5 gal. |
These numbers are estimates based on the actual surface area being painted. Since paint is typically sold in standard container sizes, you’ll generally need to round up when determining how much to purchase.
What Affects Paint Coverage Per Square Foot?
Not every surface will get the same coverage from a gallon of paint. Factors that can affect how much paint you need include:
- Surface porosity: Bare or porous surfaces may absorb more paint.
- Texture: Rough and heavily textured surfaces generally require more paint than smooth surfaces.
- Number of coats: Two coats require approximately twice the coverage of one coat.
- Application method: Brushes, rollers, and sprayers can produce different paint coverage rates.
- Surface condition: Repairs and uneven areas can affect coverage.
- The paint you’re using: Coverage varies between products, so check the manufacturer’s specifications.
Is House Square Footage the Same as Paintable Square Footage?
No. A 1,500-square-foot house does not have only 1,500 square feet of paintable surface. A home’s listed square footage generally refers to its floor area, while the amount of paint you need depends on the surface area of the walls and other surfaces you’re actually painting.
For example, the number of rooms, wall heights, layout, doors, and windows can cause two 1,500-square-foot homes to have different amounts of paintable wall area.
For estimates based on the size of an entire home, see our guides:
- Painting a 1,500-square-foot interior
- Painting a 2,000-square-foot interior
- Painting a 2,500-square-foot interior
If you’re calculating an individual room or another project, our guide to how many gallons of paint you need goes into more detail on measuring walls, rooms, ceilings, and other surfaces.
Get Help Calculating How Much Paint You Need
Not sure how much paint to buy? Bring your measurements and project details to Loconsolo Paints. Our knowledgeable team can help you estimate how much Benjamin Moore paint you’ll need and choose the right products for the job.
Visit one of our NYC paint store locations for paint, primer, and everything else you need for your project.