Paint Coverage Calculator
Most paint is wasted or short-bought at the estimate, not the roller: people skip the door-and-window deductions, forget that textured walls drink an extra gallon, or round a 2.1-gallon job to two cans and come back for a quart that doesn't match. This takeoff does the subtraction for you — wall area or room dimensions, openings deducted, texture-adjusted coverage, coats, primer and a touch-up margin — and prints the exact shopping list in gallons and quarts plus what the cans will cost in your state. It's the quantity half of the job; the Paint Cost Calculator prices the labor.
Published Cost data last reviewed Re-checked quarterly
Room dimensions assume every room matches the size below; measuring is more accurate.
Used in room-dimensions mode — hallways and landings count as one room each.
Used in room-dimensions mode.
Wall area per room = (length + width) × 2 × ceiling height.
Ignored in wall-area mode — your measurement already includes it.
Each standard door deducts 20 sq ft you don't paint.
Each window deducts 15 sq ft.
Texture, stucco and bare drywall absorb noticeably more paint.
Two coats is standard; dark or bold color changes usually need three.
Adds one sealing coat at 300 sq ft per gallon.
Touch-up paint must come from the same dye lot — buy it with the job.
Only affects the dollar estimate; the gallon count is the same either way.
Costs are adjusted for labor and material rates in your state.
Low
$330
Typical
$410
High
$560
Prices adjusted for Texaslabor & material costs.
| Cost item | Low | High |
|---|---|---|
| Materials | ||
| Wall paint — 7.4 gal for 2 coats (buy 8 gallons + 1 quart) | $290 | $480 |
| Rollers, trays, tape & drop cloths | $40 | $80 |
| Estimated total | $330 | $560 |
What this estimate assumes
- Range is 80%–135% of the computed cost — the gallon prices vary by brand and tier ($20–$50 for interior latex, more for paint-and-primer lines), not by the math.
- Wall area derived as 4 rooms × (12 + 12) × 2 ft of perimeter × 8 ft ceilings = 1,536 sq ft.
- Minus 6 doors (20 sq ft each) and 8 windows (15 sq ft each) → 1,296 sq ft of paintable wall.
- Coverage at 350 sq ft per gallon per coat for average walls; each of your 2 coats needs 3.7 gallons.
- Buy plan includes +10% for touch-ups; totals price the actual cans at $45/gallon (better (premium acrylic)), rounded up the way stores sell them.
- A takeoff, not a labor quote: quantities and material dollars only, scaled by your state's material prices. For installed cost use the Paint Cost Calculator.
Typical cost ranges
| Project | Low | Typical | High |
|---|---|---|---|
| 10×10 room — 1.6 gal → buy 2 gallons (paint cost) | $110 | $140 | $190 |
| 12×12 room — 2.0 gal → buy 2 gallons + 1 quart (paint cost) | $120 | $150 | $200 |
| 14×14 room — 2.4 gal → buy 2 gallons + 3 quarts (paint cost) | $140 | $170 | $230 |
| 16×14 room — 2.5 gal → buy 3 gallons (paint cost) | $150 | $180 | $250 |
| Project | Low | Typical | High |
|---|---|---|---|
| 1,000 sq ft home — 6.4 gal → buy 7 gallons + 1 quart (paint cost) | $310 | $380 | $520 |
| 1,500 sq ft home — 9.5 gal → buy 10 gallons + 2 quarts (paint cost) | $430 | $530 | $720 |
| 2,000 sq ft home — 12.7 gal → buy 14 gallons + 1 quart (paint cost) | $570 | $710 | $960 |
| 2,500 sq ft home — 15.9 gal → buy 17 gallons + 2 quarts (paint cost) | $690 | $860 | $1,160 |
| 3,000 sq ft home — 19.1 gal → buy 21 gallons + 1 quart (paint cost) | $830 | $1,030 | $1,400 |
| Project | Low | Typical | High |
|---|---|---|---|
| 1 coat — 1.0 gal → buy 1 gallon + 1 quart (paint cost) | $80 | $100 | $140 |
| 2 coats — 2.0 gal → buy 2 gallons + 1 quart (paint cost) | $120 | $150 | $200 |
| 3 coats — 3.0 gal → buy 3 gallons + 2 quarts (paint cost) | $160 | $210 | $280 |
| Project | Low | Typical | High |
|---|---|---|---|
| 500 sq ft of wall — 1.7 gal → buy 1 gallon + 3 quarts (primer cost) | $30 | $40 | $50 |
| 1,000 sq ft of wall — 3.3 gal → buy 3 gallons + 2 quarts (primer cost) | $60 | $70 | $90 |
| 1,500 sq ft of wall — 5.0 gal → buy 5 gallons (primer cost) | $80 | $100 | $140 |
| 2,000 sq ft of wall — 6.7 gal → buy 6 gallons + 3 quarts (primer cost) | $110 | $140 | $180 |
| 3,000 sq ft of wall — 10.0 gal → buy 10 gallons (primer cost) | $160 | $200 | $270 |
Frequently asked questions
How many gallons of paint do I need for a 12×12 room?
A 12×12 room with 8-ft ceilings has 384 sq ft of wall; after one door and one window you're painting about 349 sq ft. At the usual 350 sq ft per gallon, two coats take 2.0 gallons — 2.0 gal → buy 2 gallons + 1 quart. Buy it all at once so every can is the same dye lot.
How many square feet does a gallon of paint actually cover?
Plan on 350–400 sq ft per coat on smooth walls, and closer to 300 on rough, textured or unprimed porous surfaces — the ranges Lowe's, Sherwin-Williams and Behr publish all land there. Dark or bright colors over a light wall often need a third coat, which is coverage arithmetic, not a paint defect.
Should I subtract doors and windows from the wall area?
Yes — painters deduct about 20 sq ft per standard door and 15 sq ft per window, which is exactly what this calculator does. On a whole 2,000 sq ft home that's roughly 170 sq ft you don't paint, about half a gallon per coat. Don't deduct trim, baseboards or ceilings: cut-in areas usually consume the savings.
When is a quart enough instead of a gallon?
A quart covers about 100 sq ft per coat — one coat for a small bathroom, an accent wall under 8×10, or trim and shutters. Quarts also make the best touch-up cans: that's why the buy plan rounds the leftover fraction of a gallon up to quarts instead of forcing a whole gallon.
How many gallons of primer do I need?
Primer covers less than paint — figure 200–300 sq ft per gallon; this tool uses 300, the same figure our Paint Cost Calculator assumes. One 1,000 sq ft sealing coat needs 3.3 gallons, so buy 3 gallons + 2 quarts. Prime new drywall joint compound, smoke or water stains, glossy surfaces, and heavy dark-to-light color changes.
Is a 5-gallon bucket cheaper than single gallons?
Compare the per-gallon math on the shelf tag: on the same product line a bucket usually edges out single gallons — house brands discount buckets hardest — but premium lines sometimes price them the same, so it's a tag-by-tag call. Coverage is fixed either way: one bucket spreads about 1,750–2,000 sq ft per coat. Buckets make sense once the whole job needs 5+ gallons — a two-coat repaint of more than roughly 900 sq ft of wall; below that, gallons plus a quart avoid mixing and half-used-bucket storage.
How much paint does a ceiling add?
A ceiling is roughly the floor area — 144 sq ft for the 12×12 room — so one gallon covers a typical ceiling in a single coat. Add that footage to your wall total before deductions if you're painting both the same color; otherwise budget a separate can, because ceilings usually take flat ceiling paint that hides roller texture and laps in a way wall paint doesn't. Two caveats: textured (popcorn) ceilings drink noticeably more and are normally sprayed rather than rolled, and the cut-in overlap along the ceiling line is exactly why painters don't deduct either side's footage for it.
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Open calculatorHow this estimate is calculated
These notes are written for this tool alone: where its base prices come from, how the low–high window is derived, and what the figure deliberately leaves out.
- Wall area comes either from room dimensions ((length + width) × 2 × ceiling height × room count) or your measured square footage; doors (20 sq ft) and windows (15 sq ft) are then deducted to get paintable wall.
- Coverage is 400 / 350 / 300 sq ft per gallon per coat for smooth / average / rough-textured walls, inside the 350–400 range Lowe's and Sherwin-Williams publish and This Old House repeats (paint covers less on porous or textured surfaces).
- Primer, when selected, adds one sealing coat at 300 sq ft per gallon — the top of the 200–300 sq ft primer coverage range and the same figure the Paint Cost Calculator prices, so the two tools never disagree on a priming coat.
- Gallons are exact (area × coats ÷ coverage); the buy plan rounds up to the cans stores actually sell — whole gallons plus quarts — with an optional +10–15% touch-up margin.
- Dollars price the rounded cans at $25/$45/$70 per gallon (good/better/premium), consistent with interior latex at $20–$50/gal and paint-and-primer lines at $35–$65/gal (HomeGuide, 2025); supplies add $45 plus $0.01 per sq ft.
- Every line is materials-only and scales with your state's materials multiplier — there is no labor line in a takeoff. Ranges are 80%–135% of the computed cost, reflecting paint price spread, not quantity uncertainty.
- Excludes ceilings and trim (measure them as extra wall area if you're painting both sides), spray-gun loss (spraying uses more than rolling), and any labor.
Sources
Every cost constant above traces to the publishers listed here — the editorial gate requires at least two independent sources per calculator, each with the month we accessed it. FixTally is not affiliated with any of them.
- This Old House — How Much Paint Do I Need? (paint 350–400 sq ft/gal; primer 200–300 sq ft/gal; quart ≈ 100 sq ft; round up to whole cans — page updated June 2026) — accessed 2026-09
- HomeGuide — How Much Does a Gallon of Paint Cost? (interior latex $20–$50/gal; paint-and-primer $35–$65/gal, 2025) — accessed 2026-09
Maintained by the FixTally Editorial Team — each quarter we re-check the cited prices, re-run every calculator’s math, and refresh the review dates shown on these pages.
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