Exterior House Painting Calculator
Estimate exterior painting costs by siding type, stories, and paint quality.
Includes prep, labor, and materials.
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.