Interior Paint Cost Basics
Updated November 1, 2026
Interior paint cost starts from gallons you can buy, then a price per gallon. This page prices the wall paint for one room and keeps the other cans out of that total. The gallon steps are How to Calculate Paint for One Room. The Paint Calculator is four walls, the coats you enter, and the coverage on the can. It rounds up to whole gallons and can price those gallons.
The gallons the price sits on
The room is 12 feet by 10 feet, with 8 foot walls, two doors, two windows, two coats, 350 square feet per gallon, and 10 percent waste. Paintable walls are 280 square feet. Two coats are 560 square feet. Exact gallons are 1.60, with waste 1.76, and the purchase rounds up to 2 gallons. One gallon does not finish the second coat.
Blank price: the illustrative range
Leave the price blank and the calculator uses an illustrative $38 per gallon stored on the tool. It is a round planning figure, not a shelf tag.
- Mid: 2 × $38 = $76.00.
- Low: $64.60, which is 15 percent under that example.
- High: $91.20, which is 20 percent over it.
All three are marked Illustrative. The result says the site does not look up live prices.
Type the price on the can
Put the mid price from the can you will buy into the mid field. At $40 per gallon the mid is 2 × $40 = $80.00 and is marked Your price. Low and high become $68.00 and $96.00, the spread around the mid you typed. They stay Illustrative unless you fill those boxes too. The purchase is still 2 gallons. A different coverage on the can changes the gallons first. Change the coverage field before you trust the dollars.
Cans this range leaves out
The ceiling of this room is 12 × 10 = 120 square feet. One coat at 350 square feet per gallon is about 0.34 gallons before waste. That amount is not inside the 2 wall gallons. How Much Paint for a Ceiling? works a ceiling on its own. Buy ceiling paint as its own can if you are painting it.
Primer is another can. How Much Primer for One Room? calls for 2 gallons of primer on this same room, at the coverage on the primer can. Those 2 gallons are primer only. They do not sit inside the $76 or the $80 of finish paint.
One accent wall is a smaller buy. How Much Paint for One Accent Wall? is 1 gallon on its 12 by 8 foot example. Do not use this room's 2 gallons for a single wall.
Tape, rollers, trays, and labor are outside the per-gallon field. The range on this page is finish paint for the four walls.
FAQ
Is $76 the cost to paint the room?
It is the illustrative mid for 2 gallons of wall paint at $38 per gallon. Low is $64.60 and high is $91.20. All three are marked Illustrative when the price fields are blank. The 2 gallons are the four walls on the one-room example. The ceiling, primer, rollers, and labor are separate.
What if the can in my hand is $40 a gallon?
Type 40 in the mid price. The mid becomes $80.00 and is marked Your price. Low and high become $68.00 and $96.00, a spread of 15 percent under and 20 percent over the mid you typed. Those two stay Illustrative unless you fill them yourself. The gallon count stays at 2.
Does this range include primer?
No. The paint calculator has no primer field. On this same room the primer guide calls for 2 gallons of primer at the coverage on the primer can. That is a second purchase at the primer price. It does not sit inside the $76 wall-paint mid.
Does this range include the ceiling?
No. This room's ceiling is 12 by 10, which is 120 square feet, and the wall calculator does not add it. One coat at 350 square feet per gallon is about 0.34 gallons before waste, which is still a separate can. The ceiling guide works a different room in full. Keep the ceiling off the wall-paint total.
Use the calculator
The Paint Calculator turns this 12 by 10 foot room into 2 gallons of wall paint. With the price blank, the cost range uses the illustrative price per gallon stored on the tool. Type a mid price per gallon to replace it. Ceiling paint and primer stay off that range. The result is a planning quantity, not a contractor bid or a store quote.
If a step here does not match the result you get, email [email protected] with the measurements you entered.