How to Estimate Painting Jobs (Interior & Exterior)

Painting estimates win or lose on two things: accurate square footage and a believable price. Here is the framework.

Step 1: Measure properly

• Interior walls: linear feet of walls × wall height − doors (21 sf each) − windows (15 sf each).
• Ceilings: room length × width.
• Trim: linear feet of baseboards + door/window casings.
• Exterior: outside perimeter × height, less large openings. Add 10% for textured siding.

Step 2: Materials cost

A gallon of contractor-grade paint covers ~350 sf with one coat on primed walls. Two coats is standard.

Rule of thumb:

• Wall paint: $35–$50/gal.
• Ceiling paint: $25–$35/gal.
• Trim enamel: $50–$70/gal.
• Primer: $25–$35/gal (only as needed).
• Sundries (rollers, tape, plastic, caulk): 8% of paint cost.

Step 3: Labor

Production rates for a 2-person crew:

• Walls (2 coats, prepped): 150–200 sf per hour.
• Ceilings (sprayed, masked): 300 sf per hour.
• Trim (brushed, 2 coats): 40–60 linear feet per hour.
• Exterior siding (sprayed + back-rolled): 200 sf per hour.

Charge your loaded labor cost ($45–$65/hour per painter in most markets) and don't forget setup and cleanup (1–2 hours per day).

Step 4: Add margin

Take your direct cost (materials + labor) and mark up:

• Residential interior: 40–55% gross margin.
• Residential exterior: 45–60% (more weather/access risk).
• Commercial: 20–35% (volume offsets the margin).

Sample: 1,500 sf interior repaint

• Walls: 4,500 sf · ceilings: 1,500 sf · trim: 600 lf
• Materials: ~$650
• Labor: ~$2,400 (40 crew-hours)
• Direct cost: $3,050
• Price at 50% GM: $6,100

Build this once in BusyBuddy's estimate software as a template and you'll knock out an estimate in 10 minutes flat from then on. Start free.