When it comes to home painting projects, one of the most common questions is “How much paint will I need?” The answer depends on a few key factors, most notably the type of paint and the surface being painted. Sherwin-Williams is one of the most popular paint brands, known for its high quality and wide selection of paints. So how much does a gallon of Sherwin Williams paint cover?
Quick Answer
On average, one gallon of Sherwin Williams interior or exterior paint covers 350-400 square feet. However, the exact coverage depends on the specific paint type and finish, surface porosity, application method, and number of coats. Flat or matte paints provide more coverage than glossy paints. Textured surfaces require more paint than smooth surfaces. An airless sprayer is the most efficient applicator and can stretch paint further.
What Impacts Paint Coverage
When estimating how far Sherwin Williams paint will go, there are several factors to consider:
Paint Type and Finish
Sherwin Williams offers paint in different sheens or finishes, including:
- Flat/matte – highest coverage, hides surface defects
- Eggshell – slighter higher sheen than flat, easy to clean
- Satin – mid-level sheen, popular for walls and trim
- Semi-gloss – moderately reflective finish
- Gloss – highest sheen and hardest finish
In general, the higher the sheen, the lower the coverage. Flat or matte paints have the best coverage at around 400 sq ft per gallon. Gloss paint has a harder finish and covers around 300-350 sq ft per gallon.
Primer vs. Paint
Primers provide better coverage than paints and require less product. A primer coats surfaces more evenly and seals the substrate. On average, one gallon of Sherwin Williams primer covers up to 400-450 sq ft.
Paint Quality
Higher quality paints contain more solids, including pigments and resins. These solids improve hiding power and durability. Quality paints like Sherwin Williams provide optimum coverage and may cover more area than cheaper paints.
Surface Type
Rough or textured surfaces require more paint than smooth surfaces. Paint is absorbed by porous substrates like plaster, unpainted drywall, or wood. Non-porous surfaces like metal or vinyl siding have better coverage. On rough surfaces, a gallon may only cover around 250-300 sq ft.
Application Method
Using an airless sprayer results in the highest coverage compared to brushes or rollers. Sprayers apply paint more efficiently and evenly. With a sprayer, a gallon may cover over 400 sq ft. Brushes and rollers lead to overlap and waste.
Number of Coats
Two coats of paint are usually recommended for proper coverage and protection. The first coat acts as a primer and fills the surface. The second coat provides an even finish. More coats means using more paint overall and lower coverage per gallon.
Typical Coverage Rates by Paint Type
Here are the average coverage rates for different types of Sherwin Williams paint:
| Paint Type | Coverage per Gallon |
|---|---|
| Primer | 400-450 sq ft |
| Flat interior wall paint | 400 sq ft |
| Eggshell interior wall paint | 350-400 sq ft |
| Satin interior wall paint | 350 sq ft |
| Semi-gloss interior wall/trim paint | 300-350 sq ft |
| Gloss interior trim paint | 300 sq ft |
| Exterior flat house paint | 300-350 sq ft |
| Exterior gloss trim paint | 250-300 sq ft |
Factors that Reduce Paint Coverage
Certain conditions can cause paint to cover less area. Factors that decrease coverage include:
Dark Paint Colors
Darker paints contain more tint and pigment. Extra pigment gives paint its hiding power. But it also makes the paint thicker, requiring more coats and resulting in lower coverage per gallon.
Poor Surface Condition
Surfaces with defects, cracks, peeling paint or roughness will absorb more paint. These problems should be repaired before painting to ensure proper coverage.
High Temperatures
Heat causes paint to dry too fast, preventing proper penetration into the surface. This leads to premature peeling and the need for more coats. Cooler temperatures enhance coverage.
Improper Application
Using poor application techniques also reduces coverage. Brush marks, roller tracks, and thick coats waste paint. Proper application is essential for full coverage.
Poor Quality Paint
Cheaper paints contain fewer solids like binders and pigments. Less hide-covering ingredients mean lower coverage rates per gallon.
Tips to Maximize Paint Coverage
You can stretch your paint further by following these tips:
Use Primer
Priming ensures proper adhesion and evens out substrate pores. Primers are formulated for maximum spreadability.
Apply Multiple Thin Coats
Thin, even coats allow paint to spread more efficiently than heavy coats that puddle and run.
Use High Quality Paint
Higher grades like Sherwin Williams contain optimal levels of solids that improve hiding and coverage.
Use Flat Paint on Walls
Flat is ideal for walls since it hides defects and requires fewer coats than glossier paints.
Use an Airless Sprayer
Spraying provides the most efficient application for full coverage with less waste.
Cover Dark Colors with Primer
Priming first will help block the underlying dark shade requiring fewer coats of paint.
How Much Paint is Needed?
To determine exactly how much paint you need for a project:
1. Calculate Total Square Footage
Measure the length and width of each wall to find its square footage:
Wall sq ft = wall height x wall width
Add up the sq ft of all your walls, ceilings, trim, doors, etc. that you are painting.
2. Deduct 15% for Doors, Windows, etc.
Subtract 15% from the total to account for windows, doors, and other areas not being painted.
3. Divide Adjusted Area by Coverage Rate
Take the adjusted square footage and divide by the expected coverage rate per gallon.
Total sq ft / Coverage rate per gallon = Number of gallons needed
4. Buy Extra
It’s smart to add around 10% extra paint for touch-ups or uneven application.
Using these steps provides an accurate estimate of how much Sherwin Williams paint is required for any project.
Conclusion
With Sherwin Williams paint, the coverage rate ranges from 250-450 sq ft per gallon depending on the specific product, surface, application method and other factors. On average, 1 gallon covers 350-400 sq ft for interior or exterior painting. Flat paints offer the highest coverage while glossy paints cover the least area. Proper prep work and application technique also maximize paint spread. Consider the finish, substrate, method, and quality when estimating how far 1 gallon of Sherwin Williams paint will go.
