Estimate paint, labor, and cost for interior rooms, exterior projects, and light commercial spaces. Enter dimensions, pick your surfaces, and get an instant breakdown. No sign-up required.
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Capture every room on a single walkthrough. Interior and exterior areas — from bedrooms to office suites — each with their own dimensions, surfaces, and prep work.
Set paint brands, sheen levels, and coverage rates per surface. PriceTable calculates exact quantities and generates a purchase list.
Masking, patching, caulking, power washing, scraping, and lead-safe prep — each with its own production rate and material cost.
Download a PDF or CSV purchase list with quantities aggregated by container size — ready to hand to your paint store.
Convert a walkthrough into a professional, line-itemized estimate. Send it by email or text while you're still on site.
See material cost, labor cost, and profit margin before sending the quote. Know which jobs actually make money.
Whether you're a homeowner tackling a weekend project or a professional painter pricing a residential or commercial job, the math behind a paint estimate follows the same fundamental steps: measure surfaces, subtract openings, figure out coverage, and account for waste. Understanding each step helps you buy the right amount of paint and avoid costly mid-project trips to the store.
Every estimate starts with geometry. For walls, you calculate the room's perimeter (the sum of all wall lengths) and multiply it by the ceiling height. A 16 × 12 foot room with 9-foot ceilings has a total wall area of (16 + 12 + 16 + 12) × 9 = 504 square feet before exclusions.
Ceilings are simpler: length × width. Trim is usually expressed as the baseboard perimeter times the baseboard height — a common rule of thumb is 6 inches (0.5 ft) of baseboard around the perimeter. Doors are typically estimated at about 20 square feet per door face (both sides for a full repaint, one side for a touch-up).
You don't paint over windows and doorways, so their area must be subtracted from the wall total. A standard window opening is roughly 15 square feet, and a standard door opening is about 20 square feet. A room with two windows and one door would lose (2 × 15) + (1 × 20) = 50 square feet from the total wall area, bringing our example room from 504 down to 454 square feet of paintable wall space.
Paint coverage depends on the application method and the surface condition. A gallon of interior latex paint typically covers 350 to 400 square feet when applied with a brush or roller — the industry standard is about 375 square feet per gallon. Spraying is faster but uses more paint per square foot due to overspray, though it covers a wider area per gallon in ideal conditions (roughly 450 sq ft/gal of applied coverage when overspray is accounted for separately).
Textured surfaces, porous substrates, and dark-to-light color changes will all reduce effective coverage. Always add a waste factor — 10% is the standard minimum — to account for touch-ups, drips, and roller tray loss.
One coat is rarely enough. Fresh drywall, color changes, and semi-transparent finishes almost always require two coats for even coverage. If you're going from a dark color to a light one, three coats is common. The number of coats is a direct multiplier on your paint quantity: 454 sq ft × 2 coats = 908 sq ft of coverage needed.
Primer is a separate consideration from paint coats. Porous substrates (new drywall, concrete, brick) and bare surfaces strongly benefit from a dedicated primer coat applied before paint. Primer seals the surface, improves adhesion, and ensures even color. It's calculated separately: primer coverage is typically about 400 sq ft/gal. For the example room, that's 454 ÷ 400 × 1.10 waste = 1.2 gallons of primer, plus about 2.6 hours of additional labor.
Professional painters use production rates — the number of square feet a single painter can cover per hour — to estimate labor. Typical rates for interior work are:
Spray application is typically 30–40% faster than brush and roll for large open surfaces, but requires more prep time for masking. When bidding a job, experienced painters add setup/cleanup time — usually 0.5 to 1 hour per visit — on top of the production time.
The total cost of a painting project is the sum of materials (paint, primer, tape, drop cloths, roller covers) and labor. Material costs range from $30 to $70 per gallon depending on quality, with premium brands like Benjamin Moore Regal or Sherwin-Williams Emerald at the higher end. Labor rates for professional painters typically range from $40 to $65 per hour depending on market, complexity, and crew size.
A simple 12 × 16 bedroom with two coats on walls only might require 2.5 to 3 gallons and 4 to 5 labor hours — putting the all-in cost somewhere between $250 and $500 for a professional job. Larger rooms, higher ceilings, and additional surfaces push the price up proportionally.
Exterior estimates follow the same area-to-gallons logic, but the variables change. Instead of room length and width, you work with the building's perimeter and wall height, multiplied by the number of stories. Exterior substrates — wood siding, stucco, brick, fiber cement — have different coverage rates than interior drywall, with porous surfaces like stucco and brick consuming significantly more paint per square foot.
Access difficulty matters for exterior work. Two-story homes require ladders or scaffolding, which slows production rates by 50% compared to ground-level work. Three-story buildings are even slower. These multipliers are built into professional estimates but easy to forget when hand-calculating.
Exterior projects also include surfaces rarely seen indoors: soffits and eaves (calculated as perimeter × soffit depth), trim and fascia (linear feet of perimeter plus door/window casings), fences (length × height × sides), and decks (floor area plus railings and stairs). Each surface has its own area formula and production rate.
Prep work is heavier outdoors. Power washing is standard on nearly every exterior repaint — expect about 500 square feet per hour. Scraping and sanding peeling paint, caulking gaps around trim and windows, and wood repair are all common. Budget 3–6 additional hours of prep on a typical exterior compared to a comparable interior.
For a single room, mental math and a calculator work fine. But when you're pricing a 15-room repaint or a 10-suite office corridor job with different ceiling heights, multiple paint colors, exterior elevations, and prep work, the complexity multiplies fast. Professional painting estimating software like PriceTable automates the math, tracks brand preferences and coverage rates, generates purchase lists, and produces professional estimates — all from a single site walkthrough. The calculator above gives you a solid starting point; the full platform handles the rest.