Paint Calculator Square Feet
This paint calculator square feet (or paint calculator sqft, same thing) converts your total paint area into gallons needed for any number of coats. Standard interior latex covers about 350 square feet per gallon of paint on smooth drywall. Textured walls and exterior siding drop coverage to 200-300 sqft/gal. Use this paint calculator by square feet to avoid paying for extra trips to the store mid-project.
How Many Square Feet Per Gallon of Paint
How many square feet per gallon of paint depends on the surface:
| Surface | Coverage per Gallon |
|---|---|
| Smooth drywall (painted) | 350-400 sqft |
| Textured / popcorn wall | 250-300 sqft |
| Ceiling paint | 350 sqft |
| Exterior siding (smooth wood or fiber cement) | 300-350 sqft |
| Exterior stucco, brick, rough | 200-250 sqft |
| New unprimed drywall | 200 sqft (first coat) |
| Primer | 200-300 sqft |
This paint calculator by square feet uses these standard rates. A Sherwin Williams paint calculator square feet estimate will give the same number - paint coverage is a physical property of the paint, not the brand. Sherwin-Williams paint calculator square feet on their site uses 400 sqft/gal for premium Duration, 350 for standard.
Paint Calculator Sqft Example
How much paint for 800 sqft of wall at 2 coats on smooth drywall:
- Total coverage needed = 800 x 2 = 1,600 sqft
- Gallons = 1,600 / 350 = 4.57
- Order 5 gallons (rounded up)
Wall Paint Calculator Square Feet
Wall paint calculator square feet uses the smooth wall coverage (350 sqft/gal). A 12x14 room with 8 ft ceilings has (12+14+12+14) x 8 = 416 sqft of wall. Two coats needs 2.4 gallons = order 3 gallons.
Ceiling Paint Calculator Square Feet
Ceiling paint calculator square feet uses the same 350 sqft/gal rate. For a 12x14 ceiling = 168 sqft, 2 coats needs 1 gallon (168 x 2 / 350 = 0.96). Most ceilings only need 1 coat if you use a flat ceiling paint - rate drops to 0.48 gallons, or 2 quarts.
Exterior Paint Calculator Square Feet
Exterior paint calculator square feet needs the siding area in sqft, not the home footprint. Rough rule: home square footage x 1.5 gives siding area for a single-story home. So a 2,000 sqft home has roughly 3,000 sqft of siding.
Exterior paint calculator square feet home depot uses 300 sqft/gal on their paint calculator. For 3,000 sqft siding, 2 coats: 6,000 / 300 = 20 gallons. That's 4 five-gallon buckets.
Paint Calculator by Square Feet for Different Jobs
| Project | Sq Ft | Coats | Gallons (Smooth) |
|---|---|---|---|
| Bedroom (12x12) | 400 | 2 | 3 |
| Living room (14x18) | 560 | 2 | 4 |
| Kitchen | 400 | 2 | 3 |
| Ceiling (12x14) | 168 | 1 | 1 |
| 1,500 sqft whole-house walls | 4,500 | 2 | 26 |
| 2,000 sqft house exterior | 3,000 | 2 | 20 |
Sherwin Williams Paint Calculator Square Feet
Sherwin Williams paint calculator square feet on their website uses 400 sqft/gal for Duration, Emerald, and other premium lines, 350 for mid-tier (SuperPaint), and 300-350 for exterior products. Sherwin-Williams paint calculator square feet estimate matches this calc for the same surface type.
Why Coverage Drops on Some Surfaces
- Texture / popcorn: more surface area per flat foot, more paint soaks into the crevices
- Stucco, brick, rough siding: deep texture, porous material, absorbs more
- New drywall: untreated paper absorbs the first coat, acts like primer
- Dark colors: may need an extra coat for even coverage even on smooth walls
Paint Brand Does Not Change Coverage Much
High-end paints (Sherwin-Williams Duration, Benjamin Moore Aura) claim 400 sqft/gal on perfect smooth drywall. Mid-tier paints (Behr Premium Plus, Valspar) typically advertise 350 sqft/gal. The real-world difference is small; use 350 as a safe planning number regardless of brand.