Pricing paint jobs accurately is the difference between a profitable painting business and one that's constantly losing money. This guide covers the math, the rates, and the mistakes that catch painters off guard.
Step 1: Calculate Paintable Area
The foundation of every paint estimate is accurate square footage. Here's the formula:
For a room, measure the total perimeter (sum of all wall lengths) and multiply by ceiling height. A standard 12×14 room with 8-foot ceilings:
(12 + 14 + 12 + 14) × 8 = 52 × 8 = 416 sq ft of wall area
Deducting for Openings
Subtract unpaintable areas to avoid overestimating:
- Standard door: Deduct 21 sq ft (3' × 7')
- Standard window: Deduct 15 sq ft (3' × 5' average)
- Sliding glass door: Deduct 40 sq ft (6' × 6'8")
- Fireplace/built-in: Measure and deduct actual area
Some estimators skip deductions for windows and doors, using the extra paint to cover cutting-in time and waste. This is fine for quick budgets, but for competitive bidding, accurate deductions give you an edge. The extra 10–15% you save on material adds up over dozens of jobs.
Ceiling Area
If painting ceilings, the area is simply length × width of the room. For a 12×14 room, that's 168 sq ft. Ceilings typically take 15–20% longer to paint per square foot than walls due to overhead work and roller splatter management.
Step 2: Determine Coverage Rate
Coverage rate varies by paint type, surface condition, and application method:
| Paint Type | Coverage (sq ft/gal) | Notes |
|---|---|---|
| Interior Latex (smooth wall) | 350–400 | Standard drywall, previously painted |
| Interior Latex (textured wall) | 250–350 | Orange peel, knockdown, or skip-trowel |
| Primer | 300–400 | New drywall or significant color change |
| Exterior Latex (smooth) | 300–400 | Smooth siding, stucco |
| Exterior Latex (rough) | 200–300 | Rough-sawn wood, heavy stucco texture |
| Ceiling Paint | 350–400 | Flat ceiling paint on smooth drywall |
| Cabinet/Trim Enamel | 350–400 | But much slower application (brush/spray) |
Coats matter. Most interior repaints need 2 coats. Dramatic color changes (dark to light or vice versa) need primer + 2 topcoats. New drywall always needs primer + 2 coats minimum.
Step 3: Calculate Paint Quantity
Example: 1,200 sq ft of walls, 2 coats, at 375 sq ft/gal coverage = (1,200 × 2) ÷ 375 = 6.4 gallons → order 7 gallons.
Step 4: Price the Labor
Labor is the biggest component of any paint bid. There are two common pricing methods:
Method A: Price Per Square Foot
| Work Type | Rate/Sq Ft | Includes |
|---|---|---|
| Interior walls (repaint) | $1.50–$3.50 | 2 coats, light prep, cutting in |
| Interior walls (new construction) | $1.25–$2.50 | Prime + 2 coats, no furniture to move |
| Ceilings | $1.50–$3.00 | 1–2 coats flat ceiling paint |
| Trim/baseboards | $1.00–$2.50/LF | Brush or spray, 2 coats enamel |
| Doors (per door) | $75–$175 | Both sides, 2 coats, hardware removal |
| Exterior walls | $2.00–$4.50 | Power wash, scrape, prime, 2 coats |
| Cabinets (per LF of face) | $30–$60/LF | Full prep, prime, 2 coats, spray finish |
Method B: Hourly Rate
Experienced painters can cover 150–200 sq ft per hour on smooth interior walls with roller. Budget $25–$50/hour for labor, depending on market and experience level. Higher rates ($40–$65/hr) apply for:
- Exterior work requiring ladders/scaffolding
- Cabinet refinishing (spray prep and masking is labor-intensive)
- Heavy prep (wallpaper removal, skim coating, lead paint encapsulation)
- Commercial work with off-hours scheduling
Step 5: Build Your Bid
A complete paint bid includes:
- Paint material cost (gallons × price per gallon)
- Primer cost (if needed)
- Supplies (rollers, brushes, tape, drop cloths, caulk — typically $50–$150 per job)
- Labor hours × rate or area × per-sq-ft price
- Overhead + profit markup (typically 30–50% for painting contractors)
Common Paint Bid Mistakes
- Not doing a walkthrough: Photos miss texture, damage, wallpaper, lead paint risk, and ceiling height. Always walk the job before bidding.
- Forgetting prep time: Prep (taping, patching, caulking, sanding) is often 50–60% of the total labor on repaint jobs. Don't price like it's a spray-and-go.
- Underestimating trim: Cutting in around trim, painting baseboards, crown molding, and door casings adds 30–40% more labor than walls alone.
- Ignoring furniture and protection: Moving furniture, covering floors, and masking fixtures takes 1–3 hours per room on occupied repaints.
- Not specifying coats: Clearly state the number of coats in your bid. "Paint the room" is ambiguous. "2 coats of [specific paint] on all walls" is a binding specification.
- Using cheap paint pricing: Don't bid using bottom-shelf paint prices and then use premium paint on the job. Price the exact products you'll use.
Always include a "scope of work" paragraph in your bid that specifies: number of coats, paint brand/line, prep included, what's excluded (wallpaper removal, drywall repair beyond nail holes, etc.), and a timeline. This protects you from scope creep and customer disputes.