How to use the interior painting cost calculator
- Measure the room and enter length, width and wall height, plus the number of doors and windows. Openings use the same 21 sq ft per door and 15 sq ft per window as the paint calculator.
- Read the typical as a median of three dollar totals, not as a blended dollars-per-square-foot rate. The guides do not share a unit.
- Use this page for an owner-side room price. A contractor bid worksheet, with a production rate, overhead and profit, is on the painting job estimate calculator.
Why the three guides are totaled, then medianed
HomeGuide (February 2026) prices interior painting at $1–$3 per sq ft of wall surface; this page uses the $2 mid to build a HomeGuide total. HomeAdvisor (June 2026) quotes about $2.75 per sq ft of floor area for walls only (its broader $2–$6 band mixes in work that includes trim and ceilings). Fixr (January 2025) publishes room-size bands that work out to about $1.50–$3.50 per sq ft of floor for walls only; the $2.50 mid is used for the Fixr total.
A 12 × 12 ft bedroom with 8 ft walls, one door and one window has 348 sq ft of wall and 144 sq ft of floor. The three totals are $696, $396 and $360. The median is $396, and the spread is $360–$696. The spread is wide because HomeGuide’s wall-surface method prices this room higher than the two floor-area guides. Both views stay visible.
Packages that also paint the ceiling and trim are often about $3–$4.70 per sq ft of floor (Fixr’s $3–$4 entire-room band and HomeAdvisor’s about $4.70 figure). Those package rates are not averaged into the walls-only typical. Thumbtack’s whole-house figures run higher and rise with house size, so they are treated as an upper bound, not a room rate. This Old House’s $1–$4 per sq ft of floor is supporting only, because earlier This Old House cost pages have cited Angi.
A worked example: 12 × 12 ft bedroom
Gross wall area is 2 × (12 + 12) × 8 = 384 sq ft. Subtract 21 + 15 = 36 sq ft of openings to leave 348 sq ft. Floor area is 144 sq ft. HomeGuide: 348 × $2 = $696. HomeAdvisor: 144 × $2.75 = $396. Fixr: 144 × $2.50 = $360. The typical, the median of those three, is $396.
Sources & assumptions
How this calculator gets its numbers. Full method: our methodology.
- Typical cost is the median of three dollar totals for this room’s geometry, not a blended dollars-per-square-foot rate: HomeGuide mid $2 per sq ft of wall, HomeAdvisor about $2.75 per sq ft of floor (walls only), and Fixr’s walls-only mid of $2.50 per sq ft of floor.
- Openings use the same 21 sq ft per door and 15 sq ft per window as the paint-quantity calculator.
- Entire-room packages that also include ceiling and trim (Fixr about $3–$4 per floor sq ft; HomeAdvisor about $4.70) are described in the article, not averaged into the walls-only typical.
- This Old House is supporting only, because earlier This Old House cost pages have cited Angi.
Sources
- HomeGuide, How Much Does It Cost to Paint a Room? Feb 6, 2026: $1–$3 per sq ft of wall surface; 12×12 bedroom walls $380–$1,400; walls + trim + ceiling $770–$2,900.
- HomeAdvisor, How Much Does It Cost to Paint the Interior of a House? Jun 17, 2026: $2–$6 per sq ft of floor; about $2.75/sf walls only; about $4.70/sf walls + trim + ceilings.
- Fixr, Cost to Paint a Room. Jan 31, 2025: room-size bands that work out to about $1.50–$3.50 per sq ft of floor for walls only and $3–$4 for the entire room.
- Thumbtack, Interior Painting Cost. Mar 31, 2026: whole-interior Xactware figures about $3.86–$8.67 per sq ft of floor, rising with house size. Treated as an upper bound, not a room rate, and not used in the typical.
- This Old House, Interior Painting Cost. Apr 20, 2026: whole interior about $1–$4 per sq ft of floor space. Supporting only, because earlier This Old House cost pages have cited Angi; not used in the typical.
Last reviewed . Installed prices vary by region, contractor and job conditions; a written local bid wins.
Frequently asked questions
How much does it cost to paint a 12 × 12 bedroom?
Typically $396 for the walls only, the median of HomeGuide’s $696, HomeAdvisor’s $396 and Fixr’s $360 for a room with 8 ft walls, one door and one window. The spread of those three totals is $360–$696.
Why don’t you just multiply one dollars-per-square-foot rate?
The guides do not use the same unit. HomeGuide prices wall surface; HomeAdvisor and Fixr price floor area. Mixing those rates into one number would hide the disagreement, so the typical is the median of the three dollar totals for this room.
Does this include the ceiling and trim?
No. The typical is walls only. Entire-room packages that also include the ceiling and trim often run about $3–$4.70 per sq ft of floor (Fixr’s $3–$4 entire-room band and HomeAdvisor’s about $4.70), and are described in the article rather than averaged in.
How is this different from the paint calculator?
The paint calculator counts gallons. This page estimates an installed owner-side price from published guides. A contractor worksheet with labor, materials, overhead and profit is on the painting job estimate calculator.