Painting a 12 × 12 ft bedroom is the classic one-weekend project — and the classic way to end up one gallon short on a Sunday afternoon. This guide prices the job before you start: exactly how much paint the room takes, what else belongs on the shopping list, and what the materials add up to at typical US prices.
Everything below assumes a straightforward room: 12 ft by 12 ft with 8 ft ceilings, one standard door, and one window. The walls are previously painted and in good condition, and the plan is two coats of standard interior latex, walls only — no ceiling, no trim. If your room differs, the same math is built into the calculator further down this page.
The short answer: 2 gallons of wall paint, plus basic supplies. Here is the full breakdown.
How much paint a 12 × 12 bedroom needs
- Wall area: the perimeter is (12 + 12) × 2 = 48 ft, times the 8 ft ceiling height = 384 sq ft.
- Openings: a standard door is about 21 sq ft and a window about 15 sq ft, so subtract 36 sq ft.
- Paintable area: 384 − 36 = 348 sq ft.
- Per coat at the standard coverage of 350 sq ft per gallon: 348 ÷ 350 = 0.99 gallons.
- Two coats: 0.99 × 2 = 1.99 gallons, rounded up to 2 gallons to buy.
Primer is a separate line item, not part of those 2 gallons. One primer coat over the same area also works out to 0.99 gallons, so a single gallon covers it — and you only need it for bare drywall, stains, or a dramatic color change.
Materials list and cost
Typical US prices, checked November 2026 — the same figures used on our Paint Calculator page. Materials only.
| Item | Quantity | Typical cost |
|---|---|---|
| Interior wall paint, standard latex | 2 gallons | $50–$90 ($25–$45 per gallon) |
| Primer (only for bare drywall, stains, or a big color change) | 1 gallon | $15–$30 |
| Painter’s tape, 1.5 in | 1 roll | $5–$8 |
| Roller kit (9 in frame, covers, tray) | 1 kit | $12–$18 |
| Canvas drop cloth | 1 | $10–$15 |
Total cost
Paint and supplies come to about $80–$130 if the walls only need paint, or about $90–$160 with a gallon of primer in the cart. The paint itself is most of it — switching to premium paint at $45–$70 a gallon would push the two gallons alone to $90–$140.
Hiring it out instead: a painter typically charges about $350–$800 to paint a bedroom this size, paint included, depending on your area and how much prep the walls need. The DIY savings are real — but so is the weekend.
Calculate your own project
Different room, higher ceilings, or an extra window? Our Paint Calculator runs the same calculation with your measurements — wall area, openings, coats, and a coverage rate you can lower for textured walls.
The job in six steps
- Prep: move or cover the furniture, pull nails, fill holes, let the filler dry, sand smooth, and wipe off the dust.
- Mask: tape the baseboards, trim, and ceiling line, and put the drop cloth down before any can is opened.
- Prime if your situation calls for it (bare drywall, stains, dark-to-light color change) and let it dry fully.
- First coat: cut in the edges with a brush, then roll the walls, keeping a wet edge as you go.
- Second coat after the recoat time printed on the can — usually 2–4 hours — applied the same way.
- Finish: pull the tape while the final coat is still slightly wet for a clean line, and keep the leftover paint, sealed and labeled, for touch-ups.
FAQ
How many gallons of paint do I need for a 12 × 12 bedroom?
Two gallons. The paintable wall area is 348 sq ft after subtracting a door and a window, and two coats at 350 sq ft per gallon comes to 1.99 gallons — which rounds up to 2, with a little left over for touch-ups.
What if my ceilings are 9 ft instead of 8 ft?
The walls grow to 432 sq ft, the paintable area to 396 sq ft, and two coats need 2.26 gallons — so buy 3 gallons. One extra foot of ceiling height is the most common reason this room breaks the 2-gallon rule.
Can I get away with one coat?
For a same-color refresh over walls in good condition, one coat is 0.99 gallons, so a single gallon does it. Color changes and tired walls almost always show through after one coat, though — two thinner coats look better and last longer than one heavy one.
Do I need primer?
Only in specific cases: bare drywall (which drinks paint unevenly), stains that might bleed through, or a strong color change. Previously painted walls in decent shape take finish paint directly.
Does this budget include the ceiling?
No — this is walls only. The ceiling is another 144 sq ft, which is 0.41 gallons per coat, so one gallon of ceiling paint ($20–$35) covers two coats with plenty to spare.
More room projects
For a quick area-to-gallons lookup without any measuring, see the Paint Coverage Chart: How Much Paint per Square Foot. More priced-out projects like this one live in our Cost Guides — and if this bedroom is getting a new floor as well as new paint, LVP for a 200 Sq Ft Living Room: Materials & Cost shows the same kind of breakdown for flooring a slightly larger room.
Estimates only: quantities come from the standard formulas shown on this page and prices are typical US ranges checked November 2026; your costs vary by region, store, and product. Confirm measurements and prices before buying. This page estimates materials for common DIY projects; it does not cover structural, load-bearing, electrical, gas, or plumbing design — for safety-critical work, hire a licensed professional.