Exterior painting is where serious painting contractors make their money. A single exterior job can pay $5,000-15,000 or more, with healthy profit margins when estimated correctly.
But exterior work is also where the biggest mistakes happen. Weather delays, hidden rot, difficult access, and underestimated prep work can turn a profitable job into a nightmare.
This guide teaches you how to estimate exterior paint jobs accurately so you can bid confidently and finish profitably.
Site Assessment: The Foundation of Good Estimates
Never quote an exterior job without visiting the property. Photos don't show:
What to Look For
Siding condition:
- Peeling or flaking paint (extensive prep needed)
- Bare wood (primer required)
- Chalking (washing and possible primer)
- Mildew or algae growth (treatment needed)
- Damaged boards (repair or replace?)
Structural issues:
- Rotted trim or siding
- Loose boards
- Missing caulk at joints
- Fascia and soffit condition
Paint compatibility:
- What's currently on the surface?
- Oil-based over latex? Problems ahead.
- Multiple layers of old paint?
Access challenges:
- House height (1-story, 2-story, 3-story?)
- Steep slopes or landscaping
- Power line proximity
- Fence access to backyard
Substrate types:
- Wood siding (cedar, pine, hardboard)
- Fiber cement
- Stucco
- Brick or stone
- Vinyl or aluminum (typically don't paint)
- Mixed substrates
Measuring Exterior Surfaces
Wall Area
Ground measurement method:
- Walk the perimeter measuring each wall length
- Multiply by wall height to eave
- Add gable areas as triangles
Gable calculation: Triangle area = (Base × Height) ÷ 2
Example two-story colonial:
- First floor walls: 150 LF × 9' = 1,350 sq ft
- Second floor walls: 150 LF × 9' = 1,350 sq ft
- Subtract windows/doors: 300 sq ft
- Add 2 gables: 2 × (30' × 8' ÷ 2) = 240 sq ft
- Total wall area: 2,640 sq ft
Trim Measurement
Count and measure:
- Window trim (all windows × average trim LF)
- Door trim (all doors × average trim LF)
- Fascia board (linear feet of roofline)
- Corner boards
- Decorative elements
Quick window estimate: 15-20 LF trim per window average
Soffits and Overhangs
- Soffit: House perimeter × soffit depth
- Typically 1-2 feet deep
- Don't forget garage and porch soffits
Other Surfaces
- Garage doors (usually one color)
- Entry doors
- Shutters (count × size)
- Railings and balusters
- Foundation (if painting exposed portion)
Prep Work: Where Estimates Go Wrong
Most exterior estimating mistakes happen in prep:
Standard Prep (Light condition)
- Power wash: 500-800 sq ft/hour
- Light scraping: 200-300 sq ft/hour
- Spot prime: 15-20% of total area
- Caulking: 100-150 LF/hour
Moderate Prep
- Heavy pressure washing with treatment
- 50% scraping requirement
- Spot prime 30-40% of area
- Extensive caulking
- Minor repairs
Heavy Prep (Poor condition)
- Full scraping or stripping
- Wood treatment for bare areas
- Full prime coat
- Significant repairs
- May need specialized equipment
Time multipliers:
- Light prep: 1× labor estimate
- Moderate prep: 1.5-2× labor estimate
- Heavy prep: 2.5-3× labor estimate
Material Calculations
Paint Coverage
Exterior paint coverage varies by substrate:
- Smooth siding: 350-400 sq ft/gallon
- Textured siding: 250-300 sq ft/gallon
- Rough stucco: 150-200 sq ft/gallon
- Cedar shakes: 200-250 sq ft/gallon
Always calculate for two coats (body and trim)
Primer Needs
- Bare wood: 100% coverage
- Stain bleed: Stain-blocking primer
- Chalky surfaces: Bonding primer
- Color changes: Tinted primer
Other Materials
- Caulk: 1 tube per 30-50 LF
- Wood filler: As needed for repairs
- Plastic and tape for masking
- Drop cloths for landscaping
Labor Estimation
Production Rates (per painter)
Prep work:
- Power washing: 600-1,000 sq ft/hour
- Scraping (moderate): 100-200 sq ft/hour
- Sanding: 150-250 sq ft/hour
- Caulking: 100-150 LF/hour
- Priming (spot): 300-400 sq ft/hour
Painting:
- Body (brush/roll): 100-150 sq ft/hour
- Body (spray with backroll): 200-300 sq ft/hour
- Trim (brush): 50-75 LF/hour
- Windows: 6-10 per hour
- Doors: 2-4 per hour
- Soffits: 200-300 sq ft/hour
Height and Access Adjustments
- Ground level: Standard rates
- Ladder work (1-story): -10-20% productivity
- Two-story: -25-40% productivity
- Three-story or lift required: -40-60% productivity
Crew Size Planning
Consider optimal crew size:
- Small house: 2-person crew, 3-4 days
- Medium house: 2-3 person crew, 4-6 days
- Large house: 3-4 person crew, 5-8 days
Larger crews aren't always more efficient—coordination overhead increases.
Pricing Structure
Per Square Foot Pricing
Body only (siding):
- Light prep, 1-story: $1.00-1.50/sq ft
- Moderate prep, 2-story: $1.50-2.50/sq ft
- Heavy prep: $2.50-4.00/sq ft
Trim:
- Windows: $50-100 each
- Doors: $75-150 each
- Fascia: $2-4/LF
- Corner boards: $25-50 each
Complete House Pricing
By house size (moderate condition):
- 1,500 sq ft house: $4,000-6,500
- 2,500 sq ft house: $6,000-10,000
- 3,500 sq ft house: $8,500-14,000
- 5,000+ sq ft house: $12,000-22,000
These are rough ranges—always calculate specifically.
Building Your Estimate
The Formula
Total = Materials + Labor + Equipment + Overhead + Profit
Step-by-Step Example
2,500 sq ft two-story house, moderate condition:
Materials:
- Body paint: 12 gal × $45 = $540
- Trim paint: 4 gal × $50 = $200
- Primer: 4 gal × $35 = $140
- Caulk, filler, supplies: $150
- Material markup (15%): $155
- Materials total: $1,185
Labor (2-person crew, 6 days):
- Prep: 24 hours × 2 × $50 = $2,400
- Painting: 56 hours × 2 × $50 = $5,600
- Labor total: $8,000
Equipment:
- Ladder rental/wear: $100
- Sprayer use: $150
- Equipment total: $250
Subtotal: $9,435
Overhead (15%): $1,415 Profit (20%): $2,170
Final price: $13,020 (about $5.21/sq ft of house size)
Common Mistakes to Avoid
1. Underestimating prep Always assume more prep than you think. It's easier to finish early than to lose money.
2. Missing the back of the house Some estimators focus on street-facing surfaces. The back often has more problems.
3. Not checking for lead paint Pre-1978 homes may have lead. Testing and proper containment add significant cost.
4. Ignoring weather Build weather delay buffer into your timeline and pricing.
5. Forgetting about furniture Moving items, covering grills and furniture takes time.
6. Not getting deposit Always collect 25-50% before starting. Materials and labor must be covered.
Using estimating tools like SnapBid can help you systematically capture all these elements and avoid costly omissions.