Painting Cost Calculator
Interior painting, walls at two coats. Labor is priced per square foot of surface per coat, so the ceiling and a third coat cost real money. Trim, doors and ceilings are often quoted as separate line items.
Order 3 gallons (1 five-gallon pails) — one gallon covers 350–400 ft² per coat; buy a 5-gallon pail above 4 gallons — it is cheaper and one batch.
- Wall area
- 768 ft²
- Waste / cuts 5%
- + 38 ft²
- Coverage to buy
- 806 ft²
- Metric
- 71.3 m²
- Gallons (350 ft² each)
- 3
- Quarts (87 ft² each)
- 10
- Five-gallon pails5 gallons each
- 1
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Get 3 quotes for this paint job
The estimate above is a national range. A local drywall & interior contractor who sees your site can give you a firm price, and comparing 3 bids is the single biggest lever on what you pay. Tell us where the job is and we will match you with up to 3 contractors who serve your ZIP.
- Your quantities and this estimate go with the request, so you are not starting over.
- No account, no app. Contractors call or text you directly.
- One request. We do not resell your details beyond the matched contractors.
How to calculate paint by hand
Gallons = [2 × (L + W) × H (+ L × W ceiling)] × coats × (1 + extra) ÷ 350
Worked example
- Wall area: 2 × (12 + 12) × 8 = 384 ft².
- Two coats: 768 ft²; plus 5% for touch-ups = 806 ft².
- Gallons: 806 ÷ 350 = 2.3 → 3 gallons (or 2 gallons + 2 quarts).
- With the ceiling (144 ft² × 2 coats = 288 ft²): 1,094 ft² → 4 gallons — buy a 5-gallon pail.
- 1 gallon, smooth primed wall
- 350–400 ft² per coat
- 1 gallon, textured or bare
- 250–300 ft²
- 12 × 12 room, walls, 2 coats
- ≈ 2–3 gallons
- Trim & doors, average room
- ≈ 1 quart per coat
How we price this
The low, typical and high columns are the 20th, 50th and 80th percentile of published us national averages for interior latex, per gallon, delivery and labor. They are estimates for budgeting, not quotes — enter your own supplier and crew prices above to replace them. Ranges are re-checked monthly; see the methodology page for how every number on this site is derived.
- HomeAdvisor cost guides — interior painting $/ft² and per room
- Home Depot / Lowe’s paint pricing — per-gallon and 5-gallon prices
Questions crews ask
How much does it cost to paint a room?
$300–$800 for a 12 × 12 room, walls only, two coats, by a pro — $2–$4 per square foot of wall — or about $75–$150 in paint and supplies to do it yourself. Add $150–$300 for the ceiling and $100–$250 for trim.
How much do painters charge per square foot?
$1.50–$4 per square foot of wall surface for two coats, or $20–$50 per hour. Whole-house interiors run $2–$6 per square foot of floor area depending on trim and ceilings.
Is expensive paint worth it?
Usually for walls: a $50–$70 gallon covers in two coats where a $25 gallon needs three, washes better and lasts longer. The labor to apply an extra coat costs more than the paint difference.