How much it costs to paint a room yourself
A DIY cost breakdown for painting a room: gallons of paint, primer when you need it, and the rollers, tape, brushes and drop cloths.
- Updated October 10, 2026
- By the Paint Gallons editorial team
- 5 min read
The short answer
The cost of painting a room yourself comes down to one formula: gallons of paint × price per gallon, plus primer if the walls need it, plus supplies. For a typical 12 × 10 ft bedroom with 8 ft walls, two coats take 2 gallons of wall paint. With prices checked in October 2026, which vary by store and region, that room costs roughly $75 to $200 in paint and basic supplies, or roughly $105 to $265 if it also needs a coat of primer. Work out your gallons with the paint calculator, then price them with the paint cost calculator.
All prices in this guide are examples from US retailer and manufacturer websites, checked in October 2026. They vary by store and region, as well as by color base and sales, so treat them as ranges for budgeting, not quotes.
Step 1: work out how many gallons you need
Paint is the biggest line in the budget, and the gallons follow directly from the wall area. Measure the room's length, width and wall height, find the wall area with 2 × (length + width) × height, subtract about 20 sq ft per door and 12 sq ft per window, multiply by the number of coats, and divide by the coverage on the label. A gallon of interior paint typically covers about 350 to 400 square feet per coat. The guide to measuring walls for paint walks through each measurement.
The calculator plans whole gallons, then one quart for a remainder up to a quarter gallon, two quarts up to half a gallon, and another gallon above that. Buying slightly more than the estimate saves a second trip, and a sealed remainder is useful for touch-ups. The guide to paint can sizes explains when quarts or a 5-gallon bucket make sense.
Step 2: choose a price per gallon
Interior wall paint spans a wide price range. Prices checked October 2026 vary by store and region. At that time, contractor-grade and entry-level gallons at a big-box home center were listed from about $23, a mid-range paint-and-primer line was listed at about $38, and one Benjamin Moore line was listed on the maker's own site at about $61 a gallon.
Price per gallon is not the whole story. A better paint can hide the old color in fewer coats, which matters more than a few dollars saved per can when the color change is large. For a same-color repaint on sound walls, a mid-range paint is usually enough. Whatever you choose, use that product's stated coverage when you work out the gallons, because coverage figures differ between lines; one manufacturer states 400 to 450 sq ft per gallon for one of its lines.
Step 3: decide whether you need primer
A previously painted wall in good condition, getting a similar color, usually needs no separate primer. Plan for primer on bare new drywall, on patched or stained walls, and before a large change from a dark color to a light one. Primer covers less area than finish paint: one manufacturer puts it at about 200 to 300 square feet per gallon. Water-based interior and drywall primers were listed at about $15 to $31 a gallon in October 2026, with specialty stain-blocking primers costing considerably more.
The guide on how many coats of paint explains when a primer coat replaces or adds to the finish coats.
Step 4: add supplies
If you are starting without tools, you need a roller frame, roller covers and a tray, an angled brush for cutting in along the ceiling and corners, painter's tape, and a drop cloth. You may also want a stir stick, a sanding sponge and spackle for nail holes; these are inexpensive and often already in a toolbox. Supplies can be reused for the next room, so they cost most on the first job.
The table lists example price ranges seen at a big-box home center in October 2026. The low end assumes basic items, such as a simple roller set and a non-woven drop cloth; the high end assumes a pro-grade roller set and a large canvas drop cloth that will last for years.
| Item | Quantity for one room | Example price range |
|---|---|---|
| Interior wall paint | Per gallon | $23 to $61 |
| Interior primer (if needed) | Per gallon | $15 to $31 |
| Roller frame, covers and tray set | 1 set | $10 to $25 |
| Angled sash brush, 1.5 to 2 in. | 1 | $6 to $12 |
| Painter's tape, 60 yd roll | 1 roll | $6 to $8 |
| Drop cloth, non-woven to 9 × 12 ft canvas | 1 | $6 to $35 |
| Supplies subtotal | Roller set, brush, tape, drop cloth | $28 to $80 |
Worked example
Take a room 12 ft long and 10 ft wide with 8 ft walls and one door. The gross wall area is 2 × (12 + 10) × 8 = 352 sq ft. Subtract 20 sq ft for the door to get 332 sq ft of paintable wall. Two coats at 400 sq ft per gallon need 332 × 2 ÷ 400 = 1.66 gallons, which rounds to 1.7 gallons. After one gallon the remainder is more than half a gallon, so the paint calculator plans 2 gallons.
Paint: 2 gallons × $23 = $46 at the low end and 2 gallons × $61 = $122 at the high end. Supplies from the table: $10 + $6 + $6 + $6 = $28 at the low end and $25 + $12 + $8 + $35 = $80 at the high end. Paint plus supplies is $46 + $28 = $74 to $122 + $80 = $202, or roughly $75 to $200.
If the walls are new drywall and need one coat of primer first, 332 sq ft at 200 to 300 sq ft per gallon is 1.66 to 1.11 gallons, which round to 1.7 and 1.1 gallons. The calculator would plan 2 gallons at the lower coverage rate and 1 gallon plus 1 quart at the higher one. Primer quart prices were not checked for this guide, so the budget here uses 2 gallons, which also covers the thirstier end of the range. At $15 to $31 a gallon that adds $30 to $62, bringing the total to $74 + $30 = $104 up to $202 + $62 = $264. New drywall also absorbs more of the finish coats, so check the estimate again with the drywall setting in the paint calculator. To try other prices or rooms, use the paint cost calculator.
Ways to keep the cost down
Measure before you shop, so you buy the right number of gallons rather than a spare that sits in the garage. Choose a paint that covers in two coats instead of a cheaper one that needs three; one extra coat on the example room is close to another gallon. Reuse rollers and brushes by cleaning them well with water after latex paint, and keep the tray and drop cloth for the next room. Finally, watch for sales and multi-can discounts at the store, which can change the price per gallon noticeably from week to week.
Sources
- The Home Depot, interior eggshell gallon paint listings (prices checked October 2026)
- Benjamin Moore, Ben Interior Paint product page (price and coverage per gallon)
- The Home Depot, interior primer gallon listings (prices checked October 2026)
- The Home Depot, paint roller kit listings (prices checked October 2026)
- The Home Depot, BEHR PREMIUM PLUS 1 gal. Eggshell Enamel Interior Paint & Primer (price checked October 2026)
- Sherwin-Williams, Paint calculator: coverage of paint and primer per gallon