- Interior walls run about $1 to $2 a sq ft of wall. Exterior runs about $1.85 to $4.20 a sq ft of siding.
- A gallon covers 350 to 450 sq ft a coat. Two coats on 1,450 sq ft takes about 9 gallons.
- Labor is most of a paint job: 75% to 95% of the price, per HomeAdvisor.
How much does painting cost per square foot
These are the rates the calculator uses, combined from the cost guides listed under the calculator. Low is the average of the guides' lows, high the average of their highs, typical sits in the middle.
| Surface | Low | Typical | High |
|---|---|---|---|
| Interior walls, per sq ft of wall | $1.00 | $1.50 | $2.00 |
| Ceilings, per sq ft | $0.75 | $1.75 | $2.75 |
| Baseboards and trim, per ft | $1.00 | $2.00 | $3.00 |
| Exterior siding, per sq ft | $1.85 | $3.03 | $4.20 |
| Power washing, whole house | $240 | $320 | $400 |
| Scraping and stripping, per sq ft | $0.50 | $1.25 | $2.00 |
Interior walls and trim come from This Old House alone, and power washing and scraping from HomeAdvisor alone, so their low and high are that guide's own figures. HomeAdvisor and Fixr price interior painting per square foot of floor, which is a different measure.
Note the area. Interior wall prices are per square foot of wall, not floor. A 12 by 12 room with 8 ft ceilings has 144 sq ft of floor but about 340 sq ft of wall once a door and two windows are taken out. Quotes per square foot of floor run higher per foot for that reason.
How to measure a room or a house for paint
Inside. Add up the length of the walls (the room's perimeter) and multiply by the ceiling height. Take off 21 sq ft for each door and 12 sq ft for each window, the deductions HomeAdvisor uses. The ceiling is length times width. Baseboard is the perimeter.
Outside. For each side of the house, multiply the wall length by its height. Add the gable triangles: half the width times the gable height. Take off the doors and windows the same way. That is the paintable area the calculator asks for.
Count the pieces as well as the area. Doors, windows, shutters, railings and built-ins are slow, careful work. Fixr prices windows and doors at $35 to $50 each, and This Old House puts interior doors at $40 to $100. Put them on their own lines rather than burying them in the square-foot price.
Walk the job with the customer before you price it. Note every crack to fill, every stain to prime and every patch of peeling paint. Those notes become the prep lines on the estimate and the answer when someone asks why the price is higher than the online average.
How many gallons of paint do I need
Paint area times coats, divided by what a gallon covers. Makers and guides put a gallon at 350 to 450 sq ft a coat on smooth, primed walls: HomeAdvisor says about 350, This Old House 350 to 400, Fixr about 400, and Benjamin Moore lists 400 to 450 for Regal Select. The calculator uses 350, the low end, so the job does not run short.
| Paint area | 1 coat | 2 coats |
|---|---|---|
| 400 sq ft (one bedroom's walls) | 2 gal | 3 gal |
| 1,000 sq ft | 3 gal | 6 gal |
| 1,450 sq ft | 5 gal | 9 gal |
| 2,000 sq ft (a small house's siding) | 6 gal | 12 gal |
Rough siding, stucco, bare wood and a big colour change all take more. Buy in 5 gallon buckets once the job goes past about 4 gallons of one colour.
What changes the price of a paint job
- Labor. HomeAdvisor puts labor at 75% to 95% of a painting price. Painters charge about $25 to $100 an hour depending on the guide and the area. The calculator scales the labor share by your state's construction wage.
- Prep. Washing, scraping, patching and caulking take longer than the painting on an old house. This Old House notes that repair and cleaning can double the time.
- Height. Ladders and staging slow the crew. This Old House prices the same 2,000 sq ft home at a middle of $6,600 for one story, $9,800 for two and $11,750 for three. The calculator uses that ratio.
- Coats and colour. A big change in colour or a new surface needs primer and an extra coat.
- Paint grade. This Old House puts interior paint at $15 to $35 a gallon for value lines and $50 to $60 or more for premium.
Cost to paint a room by size
From the calculator at national prices: 8 ft ceilings, one door and two windows, two coats.
| Room | Wall area | Walls only | Walls and ceiling | Paint |
|---|---|---|---|---|
| 10 × 10 ft | 275 sq ft | $280 to $550 | $350 to $830 | 2 to 3 gal |
| 12 × 12 ft | 339 sq ft | $340 to $680 | $450 to $1,075 | 2 to 3 gal |
| 12 × 16 ft | 403 sq ft | $400 to $810 | $550 to $1,325 | 3 to 4 gal |
| 14 × 20 ft | 499 sq ft | $500 to $1,000 | $710 to $1,775 | 3 to 5 gal |
This Old House puts a bedroom at $300 to $800, and HomeAdvisor puts a 120 sq ft bedroom at $240 to $720, both close to these.
Worked example: three bedrooms, walls and ceilings.
Three rooms, each 12 by 12 with 8 ft ceilings, one door and two windows each, walls and ceilings, two coats:
- Wall area per room: 48 ft × 8 ft = 384, less 21 and 24 for the openings = 339 sq ft.
- Three rooms: 1,017 sq ft of wall and 432 sq ft of ceiling.
- Walls: 1,017 × $1.00 to $2.00. Ceilings: 432 × $0.75 to $2.75.
- Total: about $1,350 to $3,225, typical $2,275.
- Paint: 1,449 sq ft × 2 coats ÷ 350 = 9 gallons.
Cost to paint a house exterior by size
From the calculator at national prices, with power washing and two coats. The area is the paintable siding, not the floor area.
| Siding area | One story | Two stories | Paint |
|---|---|---|---|
| 1,200 sq ft | $2,450 to $5,450 | $3,525 to $7,875 | 7 gal |
| 1,800 sq ft | $3,575 to $7,950 | $5,175 to $11,625 | 11 gal |
| 2,500 sq ft | $4,875 to $10,900 | $7,100 to $16,000 | 15 gal |
| 3,500 sq ft | $6,725 to $15,100 | $9,850 to $22,225 | 20 gal |
Siding type matters too. Stucco and rough wood soak up more paint and take longer to cut in than smooth lap siding. Brick that has never been painted needs a masonry primer first.
How painters price a job
Most painters price by the square foot for walls and siding, by the foot for trim, and by the piece for doors and windows. Behind that is a production rate: how many square feet a painter rolls or sprays an hour, times the wage, plus paint and sundries, plus margin.
Keep prep as its own line. It is where jobs run over, and a customer who sees "scrape and prime 400 sq ft of peeling trim" on the estimate understands why the price is what it is. Check the number with the profit margin calculator.
"Save as an estimate in Koira" turns walls, ceilings, trim and prep into lines on an estimate you can send from your phone.
Production rates are the painter's own numbers to keep. Time a few jobs: square feet of wall rolled an hour, feet of trim cut an hour, doors done a day. After a season you can price from your own crew's speed, which is more accurate than any guide. Until then, the guide ranges on this page are a fair check.
Paint is a small share of the price. HomeAdvisor puts labor at 75% to 95% of a painting job, so a better paint that covers in fewer coats often lowers the total. Quote the paint line by name and grade, so the customer can see what they are getting.
Last checked October 8, 2026. More for your trade: how painters run on Koira.