Exterior House Painting Calculator
Estimate exterior painting cost from siding type and stories.
Returns gallons of paint, labor hours, prep cost, and total for wood, vinyl, and stucco siding.
Exterior house painting has a different cost structure than interior work. It involves surface preparation (pressure washing, scraping, caulking), primer coats on bare surfaces, and weather-resistant paint formulations.
Basic Formula:
Total Cost = Paint Cost + Primer Cost + Prep Cost + Labor Cost
Where:
- Paint Cost = Gallons needed × Price per gallon
- Gallons needed = (Exterior wall area × Coats) / Coverage per gallon
- Prep Cost = varies by siding condition
- Labor Cost = Total area × Rate per sq ft
Estimating exterior wall area:
For a rectangular house: 2 × (Length + Width) × Wall Height
Add gable areas for pitched roofs: 0.5 × Base × Gable Height
Subtract about 10% for windows and doors.
Paint coverage varies by siding type:
| Siding Type | Coverage (sq ft/gal) | Notes |
|---|---|---|
| Smooth wood | 350 – 400 | Best coverage |
| Rough/textured wood | 200 – 300 | Absorbs more paint |
| Stucco | 150 – 250 | Very porous, uses most paint |
| Vinyl | 300 – 400 | Smooth surface |
| Brick | 150 – 250 | Porous surface |
| Aluminum | 350 – 400 | Good coverage |
| Fiber cement (Hardie) | 250 – 350 | Moderate absorption |
Cost per sq ft by number of stories (US averages, 2025):
| Stories | DIY Cost/sq ft | Professional Cost/sq ft |
|---|---|---|
| 1-story | $0.50 – $1.50 | $1.50 – $3.50 |
| 2-story | $0.75 – $2.00 | $2.50 – $5.00 |
| 3-story | $1.00 – $2.50 | $4.00 – $7.00 |
Height premium: Each additional story adds 20–40% to labor cost due to ladder/scaffold setup and safety requirements.
Prep work adds significant cost:
- Pressure washing: $0.10 – $0.50 per sq ft
- Scraping and sanding: $0.50 – $1.50 per sq ft
- Caulking windows and trim: $1.00 – $3.00 per window
- Lead paint removal (pre-1978 homes): $8 – $15 per sq ft
- Wood repair/replacement: varies widely
Exterior paint types:
| Type | Durability | Best For | Price Range/gal |
|---|---|---|---|
| Acrylic Latex | 10–15 years | Most surfaces | $30 – $60 |
| 100% Acrylic | 15–20 years | Wood, fiber cement | $40 – $80 |
| Alkyd/Oil-Based | 10–15 years | Trim, metal | $35 – $65 |
| Elastomeric | 15–20 years | Stucco, masonry | $50 – $100 |
Worked Example: A 2-story home with 2,400 sq ft of exterior wall area, smooth wood siding:
- Paint: 2,400 sq ft × 2 coats / 375 sq ft per gal = 13 gallons × $55 = $715
- Primer: 2,400 / 350 = 7 gallons × $35 = $245
- Labor: 2,400 × $3.50 = $8,400
- Prep (pressure wash + light scraping): 2,400 × $0.50 = $1,200
- Total: approximately $10,560
Best time to paint exterior: Late spring through early fall, when temperatures are between 50°F and 85°F (10°C to 30°C) with low humidity. Avoid painting in direct sunlight, rain, or high wind.