Free house painting cost calculator
Gallons of paint for a room or a whole house, and what the job costs once coats, primer and labor are priced at your rate.
Enter room details
Surface
Rough and bare surfaces drink more paint
Primer covers further than topcoat
Length (ft)
Width (ft)
Height (ft)
Doors (21 sq ft each)
Windows (15 sq ft each)
Coats
Coverage (sq ft per gallon)
Price per gallon ($)
Labor rate ($ per sq ft)
3D preview · drag to rotate 0°
Whole room
Include ceiling?
Quick examples for invoices
Your paint estimate to invoice
$400.00
Total to invoice - $100 paint + $300 labor
Formula text
Invoice line item template for painting
Line item
Watch the calculator fill itself in
The same panel you used above, working out a 12 by 12 room, then the trim, then an exterior. The fields change with the surface, and so does the drawing.
Your paint order
0 gal
Gallons to buy
gal = area × coats ÷ coverage
If the surface is rough
Start with the amount you need to borrow
Jump to any part to replay it. The formulas behind these numbers are set out further down the page.
From coverage to an invoice that gets paid
Working out how much paint you need is the easy part. These are the four places the money goes missing between measuring the walls and being paid for the job.
Use it as a house painting cost calculator for one room or a whole interior, or as a painting estimate calculator for a contractor pricing a commercial job: the arithmetic is the same, only the labor hours and the access change.
Quote the work, not the paint
Paint is rarely a quarter of the finished cost. Preparation is the job: filling, sanding, caulking, masking, two coats and the making good afterwards. A client who was quoted a price per can will argue about every hour of it later.
Itemize it once on a written quote and the conversation is over before it starts.
The second coat is not a rounding error
Coverage figures on a can assume a sealed, even surface in good light. New plaster, a color change or a porous exterior wall will drink the first coat, and the ten percent you add for touching in is real money across a whole house.
Paint coverage is the number everything else hangs on. Wall paint typically covers less than the can claims once the surface is porous, and ceiling paint less again because you are cutting in around edges and working overhead. Measure the area, decide the number of coats, then price the labor separately.
The profit margin calculator checks the job still pays once that is counted.
Access and height change the price
Scaffold, a tower, cutting in around a stairwell or working around furniture that has to be moved and put back can cost more than the paint on a small job. They are decisions made before the brush is opened, so they belong on the quote rather than in a conversation halfway through the week.
Invoice while the smell is still in the air
Decorating is one of the few trades where the work is unmistakably finished: the client can see it. Send the invoice the day you clear the dust sheets, while they are still pleased with it, and add late fee terms · Invoice Due Date Calculator so a slow payer has a reason to be quick.
A margin is a decision, not a calculation
The number on this page is only real once it survives the quote, the job and the wait to be paid. These are the three documents that decide whether it does, and the other two are free here as well.
Set the margin
Cost in, margin out, or name the margin you need and take the price it gives you. Check it per line rather than across the whole job.
You are hereQuote at that price
Put the price in writing with what is included, a deposit and a valid-until date, so the figure you calculated is the figure you are held to.
Open the Quote GeneratorInvoice and collect
Bill the day the work is done, with terms, a due date and a stated late fee. Waiting 60 days for payment can cost more than the job earned.
Open the Invoice GeneratorBorrowing to cover the gap between doing the work and being paid? The loan calculator prices that properly, fees included, so you can compare it against simply asking for a deposit.
How many gallons of paint for a room?
Add up the wall area, take off the doors and windows, multiply by the number of coats and divide by what a gallon covers, usually about 350 square feet on a smooth, previously painted wall. Round up to whole gallons. The room the calculator opens on, 12 by 12 feet with 9 foot walls, one door and two windows, has 526 square feet of walls and ceiling to paint: 1.50 gallons for one coat and 3.01 for two.
| Room (ft) | Sq ft | Gallons | Buy |
|---|---|---|---|
| 10 x 10 | 285 | 1.63 | 2 |
| 10 x 12 | 317 | 1.81 | 2 |
| 12 x 12 | 349 | 1.99 | 2 |
| 12 x 14 | 381 | 2.18 | 3 |
| 14 x 16 | 445 | 2.54 | 3 |
For the ceiling, add length times width: a 12 by 12 ceiling is 144 square feet, another 0.82 gallons for two coats. Textured walls take about 10 percent more, stucco 25 and bare drywall 35, which the surface setting above allows for. Primer is its own coat at its own coverage.
For a painting estimate, the same area prices the labor: the calculator multiplies it by your rate per square foot and adds the paint at your price per gallon. The rate is per square foot of surface, not per coat, so set it for the number of coats you are quoting. The total goes onto a quote as separate paint and labor lines, and the painting invoice template bills it when the job is done.
Why use a painting cost calculator instead of guessing?
Guessing cans misses the doors and windows, the second coat and the surface that drinks paint. Paintable area, gallons and cost for walls, ceilings, trim, doors and exteriors come out of the same few measurements, with coats, primer, surface and openings taken into account, plus a line you can put straight on a quote.
Gallons you can buy
Wall area is 2 x (length + width) x height, less 20 sq ft for each door and 15 for each window. A 12 x 12 room with 8 ft walls has 384 sq ft of wall; take off a door and a window and 349 is left to paint, just under a gallon for one coat.
From estimate to quote
Paint cost is gallons to buy times your price per gallon, labor is the area times your rate, and the total is the two together. The invoice line is written for you.
Six surfaces
A whole room, walls only, a ceiling, trim and baseboard, doors and windows, or an exterior, each measured the way a painter measures it.
Built for painters who quote
It works on a phone on site, and every figure stays in your browser. Interior or exterior, residential or commercial.
How much does a gallon of paint cover?
1. Interior latex - most common
350 sq ft per gallon per coat is typical; the range is 300 to 400. Example: a 400 sq ft living room at 350 coverage needs 1.14 gallons for 1 coat, so buy 2 gallons.
2. Primer - lower coverage
200 to 300 sq ft per gallon. New drywall, or going from dark to light, needs primer. Example: 400 sq ft of new drywall with primer at 250 is 1.6 gallons, so buy 2.
3. Exterior - weather and texture
250 to 350 sq ft per gallon; rough stucco runs lower. Example: 1000 sq ft of exterior at 300 is 3.33 gallons, so buy 4 gallons. Add 10 percent waste.
Quick area, gallons and cost calculators
These 4 shortcuts come from the full calculator above. Each answers one question in plain words: enter your numbers and see an instant answer.
One wall → paint needed
Enter wall length and height. We calculate area and gallons for 1 coat at 350 sq ft per gallon.
Wall Length
Wall Height
Formula: Area = Length × Height, Gallons = Area ÷ 350
Area: 96 sq ft | Paint: 0.27 gal
Example: 12 ft × 8 ft = 96 sq ft = 0.27 gallons (buy 1 gallon).
Room size → paint needed
Enter room length, width, height. We calculate total wall area for 4 walls and gallons for 1 and 2 coats.
Length
Width
Height
Formula: Wall area = 2×(Length+Width)×Height
Walls: 384 sq ft | 1 coat: 1.10 gal | 2 coats: 2.19 gal
Example: 12×12 room 8 ft = 384 sq ft walls = 1.10 gal for 1 coat, 2.19 gal for 2 coats.
Area → gallons to buy
If you know the total sq ft to paint, enter the coverage per gallon (350 is standard) and the coats. We give the exact gallons and the rounded-up amount to buy.
Total Area
Coverage
Coats
Formula: Gallons = Area ÷ Coverage × Coats, Buy = Round up
Exact: 1.14 gal | To buy: 2 gal
Example: 400 sq ft ÷ 350 × 1 coat = 1.14 gal, buy 2 gallons.
Paint cost → total invoice
Enter gallons you will buy, price per gallon, and labor. We calculate paint cost and total to invoice client.
Gallons to Buy
Price per Gallon
Labor
Formula: Paint Cost = Gallons × Price, Total = Paint Cost + Labor
Paint: $100 | Total to invoice: $400
Example: 2 gal × $50 = $100 paint + $300 labor = $400 total to invoice.
How to work out how much paint you need in five steps
Enter room length width height
Measure the room length and width in feet and the height; 8 ft is standard, 9 ft for tall rooms. Example: a 12x12 room at 8 ft has 384 sq ft of wall area. For a single wall, use wall-only mode.
Enter doors and windows
Count the doors and windows in the room. Each door takes 21 sq ft and each window 15 sq ft off the wall area. Example: 1 door and 1 window subtract 36 sq ft, leaving 348 sq ft paintable for a more accurate gallon count.
Choose coats and coverage
Choose 1, 2 or 3 coats; 2 is standard. Coverage per gallon: 350 for interior latex, 250 for primer, 300 for exterior. Exact gallons equal the paintable area divided by coverage, times coats, rounded up to buy.
Enter price and labor to invoice
Enter the price per gallon ($50 is typical) and a labor rate per sq ft ($0.75) or a flat fee ($300). Paint cost is gallons to buy times price; labor is area times rate, or the flat fee. The total to invoice is paint plus labor, plus a markup of 15 to 30 percent for profit.
Copy invoice line and create invoice
Copy the results or the invoice line-item template. Example: Painting a 12x12 room, 348 sq ft of wall, 1 coat, 1 gallon at $50 plus labor, $311 total. Paste it into the InvoiceTools invoice generator to create a professional invoice with the client name, date, terms and late fee.
Exterior painting, and what changes
An exterior job is measured the same way, perimeter times height, but four things move the number and none of them show up in the square footage.
- Siding. Smooth lap siding takes close to the coverage on the can. Rough cedar, stucco and split block soak up more, so the same wall can take half again as much paint. Set a lower coverage figure rather than adding a fudge factor at the end.
- Stories. A second story does not add paint, it adds access. Ladder time, staging and the slower pace of working off a ladder land in labor hours, not gallons.
- Condition. Scraping, sanding, filling and spot priming is the line that separates a bid that holds from one that loses money. Price prep as its own hours, on the walls that need it, rather than folding it into a rate.
- Trim, fascia and soffit. These are measured by linear foot, not area, and they carry a different rate because they are slow. Put them on their own line so the client can see what they are paying for.
Enter the exterior area and your own rate above and the calculator gives the same output: gallons, coats, labor hours and a total you can drop onto a quote or an invoice.
Cost per square foot, and why it is the wrong unit to bid on
Most people searching for a painting cost calculator are looking for a dollar figure per square foot, because that is the unit quotes get compared in. The calculator will give you one: it divides your total by the area you entered, so you can sanity check a bid against what you normally get.
It is a check, not a method. A per square foot figure averages away the two things that decide whether a job makes money, prep hours and access. Two houses of the same size, one with sound siding at ground level and one with weathered cedar on a second story, price the same per square foot and are not the same job. Bid the hours and the gallons, then look at the per square foot number to see whether you are in your usual range.
The rate you enter is your rate. Nothing on this page carries a national average, because an average from another market is not a number you can defend to a client. If you want to set the rate itself rather than check it, work it back from your costs with the service price calculator and the profit margin calculator.
Commercial work, and where it differs
Commercial painting uses the same arithmetic and a different set of constraints. Work happens out of hours or in phases, so the same wall costs more in labor. Specification is usually written, which means the coats, the product and the sheen are decided for you and the coverage figure comes off the manufacturer's data sheet rather than your judgment. Access is often the largest line on the job: lifts, staging and permits. Price those as their own lines, and keep the paint math exactly as it is here.
Paint formula and methodology
Surface area is the walls, plus the ceiling if it is painted, less 20 square feet for each door and 15 for each window. Wall area is 2 times length plus width, times height, so a 12 by 12 room with 8 foot walls has 384 square feet of wall and 349 once a door and a window come off. Gallons are the paintable area times the number of coats, times the surface factor (1.1 for light texture, 1.25 for stucco, 1.35 for bare drywall or lumber), divided by the coverage per gallon; primer, if chosen, is added as its own coat. Gallons to buy are the exact gallons rounded up. Paint cost is gallons to buy times the price per gallon, labor is the paintable area times your rate per square foot, and the total to invoice is the two added together. Markup, prep hours and access are yours to add on the quote. Nothing is stored: the calculations run in your browser.
Using this as a house painting cost calculator
The gallons are half the answer. To turn coverage into a price, take the paint and primer this page works out, multiply by what you actually pay per gallon, then add the supplies: masking, filler, rollers and the dust sheets. Labor is the hours the job takes at your own rate, and preparation is usually longer than the painting. Add access and disposal, allow about ten percent waste on materials, and you have the cost of the job rather than the cost of the paint. To put markup and overhead on top of that and produce a document you can send, use the cost estimator.
Painting estimate calculator for contractors
The same figures work the other way round when you are the one quoting. A homeowner wants to know what a room will cost. A paint contractor needs the estimate to hold: coverage, coats, preparation hours and a margin that survives a wall that turns out to need more filler than it looked like from the door.
For a commercial painting cost calculator the numbers move on three things this page already takes: area, which on a commercial job is measured rather than guessed; coats, because a color change over a dark existing finish is three rather than two; and labor, priced per square foot on large flat areas and per hour on trim, doors and anything above a ladder. Put the labor rate in as your own rate, not a number from a website.
Preparation is the line that decides whether the estimate holds. Filling, sanding, masking and moving furniture are hours that do not show in the square footage, so they go on as their own line at your hourly rate rather than being folded into the paint. The button under the result carries the gallons and the labor onto a quote as separate lines, which is the shape a customer can check and a shape that survives the argument later.
The calculator starts at one coat; set two for most repaints and three on new plaster or a heavy color change. There is no separate waste setting, because the gallons are already rounded up to whole cans. The painting invoice template is laid out for rooms and square feet when it is time to bill.
Painting questions, answered
Is this a paint cost calculator?
Yes. It is a paint cost calculator as well as a coverage calculator: enter the area, your coverage figure and your rate, and it returns gallons, coats, labor hours and the cost of the job at your own prices.
Is this a free painting estimate calculator?
Yes. Enter the area, your coverage figure and your rate, and it returns gallons, coats, labor hours and a total. Nothing is stored and there is no sign up. The estimate can go straight onto a quote or an invoice on InvoiceTools.com.
Does it work as a paint contractor estimate calculator?
That is what it is built for. It prices from your own coverage and your own labor rate rather than a market average, separates prep from painting, and produces a line you can send. A homeowner calculator gives you a range; this gives you a bid.
Can I use it for commercial painting?
Yes, with two caveats. Commercial work is usually specified, so take the coverage from the product data sheet rather than your own figure, and price access, lifts and out of hours work as their own lines. The paint math does not change.
What is the cost per square foot to paint a house?
It depends on your rate, so the calculator works it out from your numbers rather than quoting one. Enter the area and your rate and it divides the total by the area. Treat that figure as a check on a bid you built from hours and gallons, not as a way to build one.
Common questions about paint needed, coverage, cost to invoice painting jobs.
How much does it cost to paint a 1,000 sq ft house?
Start from the wall area, not the floor area: 1,000 square feet of floor can mean 2,000 square feet or more of wall and ceiling once the rooms are measured. Add up the rooms here, price them at your own rate per square foot and per gallon, then add the prep hours honestly, because prep and ceiling height move the price more than paint quality does.
How do I improve painting business profit margins?
Two levers, and neither is buying cheaper paint. Cut the time lost to prep you did not quote for by writing surface condition into the quote, and stop absorbing extra coats that were never agreed. A wall that needs three coats should be quoted as three.
How much paint do I need per square foot?
One gallon covers roughly 350 square feet in one coat on a previously painted, smooth wall. Two coats halve that to about 175 square feet a gallon, which is the figure to plan with, because one coat rarely looks finished over a color change.
How many gallons of paint for a 12x12 room?
With 9 foot walls, walls and ceiling come to 526 square feet once a door and two windows come off: 1.50 gallons for one coat and 3.01 for two, so 3 gallons and a quart. Walls only with 8 foot walls, one door and one window is 349 square feet, 1.99 gallons for two coats.
How much paint do I need for the exterior of a house?
Measure the perimeter, multiply by the wall height and add the gables, then take off doors and windows. A 120 foot perimeter at 10 feet with 80 square feet of gable is about 1,120 square feet, which is 6 to 7 gallons at two coats.
Do I need primer?
Yes on bare drywall, new timber, patched repairs and any large color change, especially light over dark. Primer covers slightly further than topcoat, so treat it as its own coat rather than adding one to the count.
How much more paint does textured or bare surface take?
Light texture adds roughly 10 percent, heavy texture or stucco 25, and bare drywall or lumber up to 35. It is the single most common reason a job runs short mid-wall.
How do I calculate paint for trim and baseboard?
By the run, not the room. Multiply the linear feet by the board width in feet, then by the number of faces you are painting. Sixty feet of 5 inch baseboard painted on two faces is about 50 square feet, which is well inside a single gallon.
How many coats of paint do I need?
Two on most walls. One is enough only when you are refreshing the same color on a sound surface, and three is realistic for strong colors, or light over dark, whatever the can claims.
How much should I charge to paint a room?
Work from the area rather than a room size, because a 12 by 12 room with 12 foot ceilings is a third more wall than one with 9 foot ceilings. Price the surface here at your own rate, add your prep hours, and check the result against what you would want for the day. With the figures the calculator starts on, $50 a gallon and $0.75 a square foot, the 526 square foot room comes to $494.50 for one coat before prep; those are placeholders to replace with your own prices, not a market rate.
Should I deduct doors and windows?
Yes, at about 20 square feet a door and 15 a window. On a small room that is over 10 percent of the wall area, which is a gallon on a large job.
How do I estimate paint for a ceiling?
Length times width, and nothing else. Ceilings often need an extra coat because they are viewed in raking light, so plan two even when the walls need one.
How much does a gallon of paint cost?
It depends on the product, the sheen and whether you buy at trade or retail, so enter what you actually pay; the $50 the calculator starts on is a placeholder. On most jobs labor is the larger part of the total, so buying cheap paint to save money usually costs more in extra coats.
Is the paint calculator free and private?
Yes. No signup, nothing uploaded, and every figure is worked out in your browser and gone when you close the tab.
What should a painting quote include?
The surfaces by name, the number of coats, whether primer is included, and what preparation is covered. Most disputes on painting jobs are about prep nobody wrote down, not about paint.
Should I quote painting by the square foot or by the day?
Square foot pricing is easier for a client to compare and easier for you to check afterwards. Day rates hide the prep, which is exactly where painting jobs lose money.
How do I charge for extra coats?
State the number of coats on the quote and price additional coats as a separate line. A wall that needs three coats because of a color change is a bigger job, and it should be a bigger number.
Should paint be a separate line on the invoice?
It usually helps. It shows the client what the materials cost, keeps your labor rate from looking inflated, and makes it obvious why a premium finish costs more.
How do you calculate house painting cost?
Measure the surfaces, take off the openings, decide coats and primer, then price paint and labor separately. Cost is materials plus labor plus the parts people forget. Work out the gallons from the wall area and the number of coats, multiply by what your paint actually costs, then add primer, masking, filler and rollers. Labor is the hours the job takes at your rate, and preparation is usually longer than the painting itself. Add disposal and access, and allow about ten percent waste on materials.
How much paint do I need for a whole house?
Measure each room and add them together rather than working from the floor area, because ceiling height and the number of windows change the answer more than square footage does. One gallon covers roughly 350 square feet per coat, so a room with 1,000 square feet of wall takes about three gallons for one coat and six for two.