Interior Painting Cost per Square Foot: Full Breakdown

Ask three painters what it costs to paint the inside of a house and you will get three different numbers. One quotes per square foot, one quotes per room, and the third quotes a day rate — and none of them will match until you know what each number actually includes. The paint itself is usually the smallest line on the bill. Labour, preparation and the number of coats are what move the price.

This guide breaks interior painting cost down the way an estimator does: measured wall area, paint quantity, labour hours, and the extras that quietly add up. All prices are US figures in dollars per square foot of floor area unless stated otherwise, reflecting typical 2025–2026 rates. Your local market will sit somewhere inside the ranges given, but the method of working the price out is the same everywhere.

What interior painting costs per square foot

For a standard repaint — two coats on walls, one coat on ceilings, walls in good condition — expect $2 to $6 per square foot of floor area. That covers the full job: paint, labour, preparation and sundries. A mid-range job in most US markets lands around $3 to $4 per square foot.

It helps to see the range split by scope, because a bare repaint and a full makeover are different jobs:

• Walls only, two coats, good condition: $2.00–$3.50 per sq ft of floor area.
• Walls plus ceilings: $3.00–$4.50 per sq ft of floor area.
• Walls, ceilings, trim and doors: $4.00–$6.00 per sq ft of floor area.
• Full job with heavy preparation (repairs, sanding, primer, dark-to-light colour change): $5.00–$7.00 per sq ft of floor area.

Those figures are per square foot of floor area, which is how most US painters quote a whole house. A 1,200 sq ft home at $3.50 per sq ft is $4,200. Be careful when a quote looks far cheaper than these ranges — check whether ceilings, trim and primer are included, because those are the items most often left out of a low headline price.

How painters price the work

There are three common pricing methods, and knowing which one your quote uses stops you comparing apples with oranges.

Per square foot of floor area

The most common method for whole-house work. The painter measures the floor area, multiplies by a rate, and that is the price. It is quick and easy to compare, but the rate hides a lot: a 1,200 sq ft house with 8 ft ceilings costs less to paint than the same floor area with 12 ft ceilings, because the wall area is far larger. Always ask what the rate includes.

Per hour or per room

A professional painter charges roughly $25 to $50 per hour, or $200 to $400 per painter per day. Day rates suit small jobs and repair work. If you are quoted an hourly rate, ask for an estimated number of hours in writing — an open-ended hourly job with no estimate is how small rooms turn into large bills. As a rough guide, painting one average room (walls and ceiling, two coats) costs $400 to $1,000.

How to measure and work out how much paint you need

Every painting estimate starts with two measurements: the paintable area, and the paint quantity that area needs. Get these right and the rest of the estimate follows.

Step 1 — Measure the wall area

Measure the perimeter of the room and multiply by the ceiling height, then subtract doors and windows:

Wall area = (perimeter × ceiling height) − doors and windows

A standard interior door is 21 sq ft (3 ft × 7 ft) and an average window is about 15 sq ft. As a quick rule of thumb for a whole house, net wall area is roughly three times the floor area — a 1,200 sq ft home has about 3,200–3,600 sq ft of wall to paint.

Step 2 — Work out the paint quantity

Most interior paints cover about 350 sq ft per gallon per coat on smooth, previously painted drywall. That is the manufacturer's figure; on bare drywall, textured walls or plaster it drops to 250–300 sq ft per gallon. The formula is:

Gallons = (paintable area × number of coats) ÷ coverage per gallon

Then add 10% wastage for cutting in, roller absorption and touch-ups, and always round up to whole gallons — running short mid-wall leaves a visible lap mark where the new batch starts.

Step 3 — Price the paint

Paint prices fall into three tiers. Contractor-grade paint runs $25–$35 per gallon and is fine for rentals and ceilings. Mid-range paint, the sensible choice for most homes, runs $40–$55 per gallon. Premium paint runs $60–$75 per gallon and earns its price on durability and washability in kitchens, bathrooms and hallways. Ceiling paint is usually cheaper at $30–$40 per gallon, and primer runs $25–$35 per gallon. Low-VOC paints, which meet EPA guidelines for indoor air quality, cost only a few dollars more per gallon in every tier.

Worked example 1 — painting one bedroom

Take a standard bedroom, 12 ft × 14 ft with 9 ft ceilings, walls in good condition, one door and one window, repainted in a similar colour with two coats on the walls and one coat on the ceiling.

Wall area: perimeter = 2 × (12 + 14) = 52 ft. Gross wall area = 52 × 9 = 468 sq ft. Subtract the door (21 sq ft) and window (15 sq ft): net wall area = 432 sq ft.

Paint quantity: walls, two coats = 432 × 2 = 864 sq ft ÷ 350 = 2.47 gallons, so buy 3 gallons of wall paint. Ceiling = 12 × 14 = 168 sq ft, one coat = 0.48 gallons, so buy 1 gallon of ceiling paint. Primer is not needed here because the colour is similar and the existing paint is sound — on bare drywall, add 2 gallons of primer.

Materials: 3 gallons of wall paint at $45 = $135; 1 gallon of ceiling paint at $35 = $35; sundries (painter's tape, drop cloths, roller covers, caulk) = $45. Materials total = $215.

Labour: one painter needs roughly 11 hours for preparation, cutting in, two coats on the walls and one on the ceiling. At $30 per hour, labour = $330.

Room total = $215 + $330 = $545. That is about $3.24 per sq ft of floor area (168 sq ft), sitting neatly inside the national $2–$6 range. If the room also needs its trim and door painted, add roughly $100–$150 for materials and a half day of labour.

Worked example 2 — painting a 1,200 sq ft house

Now scale the same method up to a whole house: 1,200 sq ft of floor area, 8 ft ceilings, three bedrooms, living room, kitchen and two bathrooms, all walls in reasonable condition.

Paintable area: net wall area ≈ 3,200 sq ft; ceilings = 1,200 sq ft; trim and doors allow about 2 gallons of enamel.

Paint quantity: walls, two coats = 3,200 × 2 = 6,400 sq ft ÷ 350 = 18.3 gallons, so buy 19 gallons. Ceilings, one coat = 1,200 ÷ 350 = 3.4 gallons, so buy 4 gallons. Primer for spot-priming repairs and the bathroom ceilings = 5 gallons. With 10% wastage the wall paint order becomes 21 gallons — in practice most painters round to 20 and keep one spare.

Materials: 19 gallons of wall paint at $45 = $855; 4 gallons of ceiling paint at $35 = $140; 2 gallons of trim enamel at $50 = $100; 5 gallons of primer at $30 = $150; sundries (tape, plastic, drop cloths, caulk, sandpaper) = $120. Materials total = $1,365.

Labour: a two-person crew needs about four days: one day of preparation and masking, two days of cutting in and rolling, one day for ceilings, trim and touch-ups. 2 painters × 4 days × 8 hours × $32 per hour = $2,048.

House total = $1,365 + $2,048 = $3,413, or about $2.84 per sq ft of floor area. In a high-cost metro area the same job runs $4,500–$6,000 because labour rates climb toward $45–$50 per hour; in a lower-cost market it can come in under $3,000. Notice the split: labour is roughly 60% of the total. That is normal for painting — anyone quoting a job where paint is the biggest line has either underpriced the labour or overpriced the paint.

What pushes the price up or down

• Preparation: filling nail holes, sanding, caulking and masking is 20–30% of the labour on a good job. Walls with cracks, water stains or peeling paint need more of it, and each extra day of prep adds $200–$400 per painter.
• Colour change: going from dark to light, or light to dark, usually needs a primer coat plus two finish coats — roughly 30–40% more paint and a day of labour.
• Ceiling height: walls above 10 ft need extension poles or scaffolding and take longer per square foot. Vaulted ceilings and stairwells are the most expensive surfaces in a house to paint.
• Trim and doors: brushing trim, doors and window frames is slow, detailed work. Budget $100–$200 per door including both sides, and $2–$4 per linear foot for baseboards and crown moulding.
• Paint quality: the jump from contractor-grade to premium paint adds about $20–$30 per gallon — roughly $400–$600 extra on a 1,200 sq ft house. Worth it in kitchens and bathrooms, hard to justify on a bedroom ceiling.
• Occupied vs empty: furniture to move, protect and work around typically adds 10–15% to the labour.
• Repairs: drywall patching, texture matching and stain blocking are usually charged separately at $50–$150 per repair, or folded into the prep allowance.

DIY vs hiring a painter

Doing it yourself saves the labour, which is 60% of the bill — but it costs your time and the finish is rarely the same. A professional rolls a room in a day; a first-timer takes a weekend and usually leaves roller marks, uneven cutting-in lines and paint on the ceiling. DIY makes sense for one or two rooms in good condition, with standard 8 ft ceilings and a colour close to the existing one. Hire a professional for whole houses, tall walls, stairwells, heavy preparation, or any job where the finish will be looked at every day. If you do go DIY, budget an extra $100–$200 for decent brushes, rollers, an extension pole and drop cloths — cheap tools are the single biggest cause of a poor DIY finish — and never skip primer on bare drywall or patched areas, or the patches will show through as dull, flat spots.

Frequently asked questions

How much does it cost to paint a 12×12 bedroom?

Expect $400–$700 professionally painted, walls and ceiling, two coats, in good condition. DIY materials for the same room run about $150–$250. Add $100–$150 if the trim and door are included.

How much paint do I need for a 1,200 sq ft house?

About 19–21 gallons of wall paint for two coats, 4 gallons of ceiling paint for one coat, and 2 gallons of trim enamel, plus around 5 gallons of primer for spot priming. Buy 10% extra and keep the remainder for touch-ups — a labelled leftover gallon is worth more than the $45 it cost.

Is one coat of paint ever enough?

Only when repainting the same colour on walls in good condition with a high-quality paint. A colour change, bare drywall, patched walls or cheap paint will show through after one coat. Two coats is the standard for a reason, and it is what the coverage maths in this guide assumes.

The bottom line is simple: measure the wall area, work out the paint at 350 sq ft per gallon per coat, add 10% wastage, and price the labour at 60% of the total. Do that and no quote will surprise you.