To calculate exterior paint, multiply each wall’s length by its height, add the totals, subtract about 20 sq ft per door and 15 sq ft per window, then divide by 350ā400 sq ft per gallon and multiply by two coats. A typical 1,500 sq ft two-story house needs roughly 10ā15 gallons; professional painting usually costs about $1.50ā$4 per sq ft of wall area. Rough or porous siding like stucco, brick or cedar shakes soaks up more paint, so plan on extra.
Exterior Paint Formula
- Wall area: length x height for each side. For gables, add (width x gable height) Ć· 2.
- Subtract openings: about 20 sq ft per door and 15 sq ft per window (or measure).
- Divide by coverage: about 350ā400 sq ft per gallon on smooth siding, 200ā300 on rough or porous surfaces.
- Multiply by coats: two coats is standard on exteriors.
- Add extra: round up and add 10% or one extra gallon for touch-ups.
Example: a 40 x 30 ft house with 18-ft walls: (40+30) x 2 x 18 = 2,520 sq ft. Subtract 2 doors and 14 windows (250 sq ft) = 2,270 sq ft. Ć· 375 = about 6 gallons per coat, so about 12ā13 gallons for two coats. Add 1ā2 gallons for trim.
Gallons Needed by House Size
| House size (floor area) | Approx. wall area | Gallons (2 coats) | Pro cost estimate |
|---|---|---|---|
| 1,000 sq ft, 1 story | 1,000ā1,300 sq ft | 6ā8 | $1,800ā$4,500 |
| 1,500 sq ft | 1,600ā2,000 sq ft | 9ā12 | $3,000ā$6,500 |
| 2,000 sq ft, 2 story | 2,000ā2,600 sq ft | 11ā15 | $4,000ā$9,000 |
| 2,500 sq ft, 2 story | 2,500ā3,200 sq ft | 14ā18 | $5,000ā$11,000 |
Estimates assume smooth siding and average prep. Add trim paint separately.
House Painting Cost Estimator
- Paint: quality exterior acrylic often costs $40ā$90 per gallon.
- Labor: usually most of the total; pros commonly charge $1.50ā$4 per sq ft of wall area.
- Height: two- and three-story homes cost more because of ladders, lifts or scaffolding.
- Siding type: stucco and brick often add about $1 per sq ft.
- Prep: scraping, power washing, caulking, carpentry repairs and priming add time.
- Lead paint: homes built before 1978 may need lead-safe work practices by a certified contractor.
DIY vs Hiring a Painter
Pros
- DIY can save 60ā80% of the cost
- Single-story homes are manageable for many homeowners
- Pros finish faster and often offer a warranty
Cons
- Ladder falls are a serious risk on tall homes
- DIY takes many weekends
- Poor prep leads to peeling within a few years
Painting a roof too? Read can you paint a metal roof, and for door color ideas see red door meaning.
