A good painting estimate starts with the wall area, turns it into paint and hours, and then adds the margin you need. Guessing by room often leaves labor unpaid.
Updated 25 October 2026. Written by Tahir Abbas, Softotech. All figures are worked examples, not quotes.
Key takeaways
- Measure wall area first, then turn it into gallons and hours. Never price by room alone.
- Labor is the largest cost in the example, so track your own sq ft per hour instead of using a guess.
- Round gallons up. A coverage figure of 350 sq ft per gallon is on the can, and a 1.03 gallon need still means buying 2.
- A 25% markup on cost is only a 20% margin, so use the margin formula if you need 25% profit.
- In homes built before 1978, painting for pay brings EPA lead-safe rules, which change cost and process.
Step 1: Measure the wall area
Example: a 12 ft by 15 ft room has a 54 ft perimeter. At an 8 ft ceiling that is 432 sq ft. Subtract one door (21 sq ft) and two windows (15 sq ft each) to get 381 sq ft.
Step 2: Work out the paint needed
Multiply by the number of coats, usually two: 381 x 2 = 762 sq ft. Check the coverage on the paint can. A gallon often covers around 350 to 400 sq ft, so at 350 sq ft per gallon you need 762 / 350 = 2.2 gallons, so buy 3.
Step 3: Estimate labor
Your speed depends on the surface, prep and how much cutting in there is. If you average 125 sq ft an hour for this kind of room, 762 / 125 = about 6.1 hours. Use your own tracked times rather than this example.
Step 4: Add up cost and price it
- Paint: 3 gallons at $40 = $120 (example price).
- Supplies such as tape, drop cloths and rollers: $30.
- Labor: 6.1 hours at $45 = $274.50.
- Total cost: $424.50.
At a 25% margin, the quote is $424.50 / 0.75 = $566. Not sure about margin and markup? Read markup and margin explained.
Things that change the estimate
- Prep work: patching, sanding, moving furniture and priming.
- Ceilings, trim and doors, which are usually priced separately.
- Dark colors that need extra coats.
- Travel time and overhead, including labor burden if you have employees.
Price a whole interior
Most jobs are more than one room. Here is a second example: three bedrooms, each the same size as the one above (381 sq ft of wall, 2 coats), plus trim and prep. All speeds and prices are examples, so use your own tracked times.
- Walls: 3 x 762 sq ft = 2,286 sq ft of paint coverage. At 125 sq ft an hour that is about 18.3 hours.
- Paint: 2,286 / 350 = 6.5, so buy 7 gallons. At $40 that is $280.
- Trim: 54 linear feet of baseboard per room, 162 feet in total. At 60 linear feet an hour that is about 2.7 hours.
- Prep: patching, sanding, taping and moving furniture, about 3 hours.
- Supplies (tape, plastic, rollers, caulk): $60.
Total labor is 18.3 + 2.7 + 3 = 24 hours. At a loaded labor cost of $22 an hour that is $528. Total cost is $280 + $528 + $60 = $868. At a 35% margin:
Price = cost / (1 – margin) = $868 / 0.65 = about $1,335, or roughly $445 a room.
If your labor cost includes payroll taxes and insurance, see how to calculate labor burden. To set your own hourly rate, see how to calculate an hourly rate.
Estimate checklist
- Ceilings, closets, doors, trim and windows are separate line items. Do not hide them inside the wall number.
- Going from a dark color to a light one may need primer or a third coat.
- Stains, repairs and heavy texture add prep time.
- Count drive time, loading and cleanup, not only brush time.
- Write down what is included, the paint brand and the number of coats in the quote.
Older homes and lead paint
In homes built before 1978, paid work that disturbs painted surfaces falls under the EPA lead-safe rules for renovation, repair and painting, and contractors must be certified and follow the rules. This changes your cost and your process, so read the EPA Renovation, Repair and Painting Program before bidding on older houses.
Sources and a note
- EPA Renovation, Repair and Painting Program for pre-1978 homes.
- U.S. Bureau of Labor Statistics: Painters, Construction and Maintenance (Occupational Outlook Handbook)
Coverage per gallon comes from the paint can, and speeds and prices are examples. Replace them with your own.
Use the calculator
Put your room sizes in the painting estimate calculator. More tools are on the free tools page.
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How do I estimate a second room with different measurements?
Run the same steps on a bigger room. Assumptions for this example: 14 x 16 ft room, 9 ft ceilings, one door (21 sq ft), three windows (15 sq ft each), two coats, 350 sq ft per gallon, 125 sq ft an hour, paint at $40 a gallon, $30 of supplies and labor at $45 an hour, the same as the first example.
- Perimeter: 2 x (14 + 16) = 60 ft.
- Wall area: 60 x 9 – 21 – 45 = 474 sq ft.
- Two coats: 474 x 2 = 948 sq ft.
- Paint: 948 / 350 = 2.7 gallons, so buy 3. Cost: $120.
- Labor: 948 / 125 = 7.58 hours x $45 = $341.28.
- Total cost: $120 + $30 + $341.28 = $491.28.
- Quote at a 25% margin: $491.28 / 0.75 = about $655.
This room is 24% more wall than the first, and the quote is 16% higher, because the paint and supplies cost the same ($150 in both rooms) and only labor grows with the wall area.
What is the difference between margin and markup on a painting quote?
If you add 25% to the $424.50 cost from the first example, you get $530.63. Profit is $106.13, but that is only 20% of the price ($106.13 / $530.63). To make 25% of the price as profit, divide by 0.75 and quote $566, as the guide does. The gap is about $35 on one small room. Read our markup and margin guide if you are unsure which your pricing sheet uses.
Do ceilings need their own line?
Yes. Ceilings are measured by floor area, not wall area, and they are usually rolled at a different speed than walls. Using the 12 x 15 ft room, ceiling area is 12 x 15 = 180 sq ft. Two coats make 360 sq ft. At 350 sq ft per gallon, that is 1.03 gallons, which means one gallon falls just short and you need a second. This kind of rounding is why small jobs often cost more per square foot than large ones. Add the ceiling as its own line with its own hours, and do the same for trim, doors and closets.
How do I sanity-check a painting estimate?
Divide your quote by the wall area it covers. For the first room that is $566 / 381 sq ft = about $1.49 per sq ft of wall. For the three-bedroom job, $1,335 / 1,143 sq ft of wall (2,286 sq ft of paint coverage over two coats) is about $1.17 per sq ft. The lower figure fits because larger jobs spread setup and cleanup over more wall. If your own jobs come out far from your usual number, look for a missed line, not a reason to change the price.
Also compare your loaded labor rate with local wages. The U.S. Bureau of Labor Statistics reports a median pay of $23.75 an hour for construction and maintenance painters in May 2025, before your payroll taxes, insurance and overhead. Your rate may be above or below that, so use your own tracked numbers.
Frequently asked questions
How do you calculate square footage for painting walls?
Multiply the room perimeter by the ceiling height, then subtract the area of doors and windows.
How much paint do I need for a room?
Divide the total wall area, counting each coat, by the coverage listed on the can, and round up to a whole gallon.
How much should a painter charge?
Charge enough to cover materials, labor, overhead and your target margin. Start from your own cost, not from what others charge.
How many coats of paint should I price for?
Two coats is the usual assumption, and this guide uses it. Price a primer coat or a third coat when you go from a dark color to a light one, cover stains, or paint new drywall. State the number of coats in your quote.
Do I need to subtract windows and doors?
Yes, subtract them from the wall area so you do not pay for paint you will not use. Trim and door faces are then priced as separate lines. Some painters subtract only large openings, so decide a rule and apply it every time.
Do I need a lead-safe certification to paint a house?
In pre-1978 housing, anyone paid to disturb painted surfaces generally must be EPA lead-safe certified, including sole proprietors. Homeowners working on their own home are generally exempt. Read the EPA page and check your state, because some states run their own program.