Every paint question is the same question: how many gallons for this much wall? This chart answers it directly. Find your paintable area — wall area minus the doors and windows you will not paint — and read across for the exact gallons and the whole gallons to actually buy, for one coat and two.
The chart uses the standard coverage rate of 350 sq ft per gallon per coat, the figure major US paint manufacturers publish for smooth, primed walls. Rough, textured, or unprimed surfaces cover less — closer to 250–300 sq ft per gallon — so treat the chart as the standard case and adjust down if your walls are thirsty.
Paint coverage chart by area
| Paintable area | 1 coat — exact | 1 coat — buy | 2 coats — exact | 2 coats — buy |
|---|---|---|---|---|
| 100 sq ft | 0.29 gal | 1 gal | 0.57 gal | 1 gal |
| 200 sq ft | 0.57 gal | 1 gal | 1.14 gal | 2 gal |
| 300 sq ft | 0.86 gal | 1 gal | 1.71 gal | 2 gal |
| 400 sq ft | 1.14 gal | 2 gal | 2.29 gal | 3 gal |
| 500 sq ft | 1.43 gal | 2 gal | 2.86 gal | 3 gal |
| 600 sq ft | 1.71 gal | 2 gal | 3.43 gal | 4 gal |
| 800 sq ft | 2.29 gal | 3 gal | 4.57 gal | 5 gal |
| 1,000 sq ft | 2.86 gal | 3 gal | 5.71 gal | 6 gal |
The same chart by room size
If you have a room rather than an area, this version skips a step. Wall area is the perimeter times an 8 ft ceiling, before subtracting openings — see the note under the table for why that matters.
| Room (8 ft ceilings) | Wall area | 1 coat — buy | 2 coats — buy |
|---|---|---|---|
| 10 × 10 ft | 320 sq ft | 1 gal | 2 gal |
| 10 × 12 ft | 352 sq ft | 2 gal | 3 gal |
| 12 × 12 ft | 384 sq ft | 2 gal | 3 gal |
| 12 × 16 ft | 448 sq ft | 2 gal | 3 gal |
| 16 × 20 ft | 576 sq ft | 2 gal | 4 gal |
Notice the 12 × 12 room: the room-size table says 3 gallons for two coats, because it counts the full 384 sq ft of wall. Subtract a typical door and window (about 36 sq ft) and the paintable area drops to 348 sq ft, which needs 1.99 gallons — so the real-world answer for that room is 2 gallons. That gap is exactly why the calculator below subtracts openings.
How to read this chart
The whole chart is one formula: gallons = paintable area ÷ 350 × coats, rounded up to whole gallons, because stores sell whole gallons (and quarts). The “exact” columns show the true consumption; the “buy” columns round up, and the difference between them is your touch-up reserve.
- Getting paintable area: measure each wall (length × height), add them up, then subtract about 21 sq ft per standard door and 15 sq ft per average window.
- Between rows? Use the next row up, or run the exact formula — or the calculator below — with your number.
- Quarts: a quart covers about 87 sq ft per coat, so quarts suit single small walls and touch-up jobs under roughly 85 sq ft. At 100 sq ft you are already past a quart (0.29 gal), which is why the chart starts at a gallon.
- Ceilings are just another area: length × width, looked up in the first table like any wall.
Run your exact numbers
Our Paint Calculator applies the same formula to your room’s dimensions, subtracts your doors and windows, and lets you change the coverage rate for textured or unprimed walls.
FAQ
How much paint do I need for 500 sq ft?
At the standard rate: 1.43 gallons for one coat (buy 2), and 2.86 gallons for two coats (buy 3). If that 500 sq ft is wall area before subtracting openings, the true figure will be a little lower.
Does primer follow the same chart?
Roughly. Primer coverage is in the same neighborhood — many cans state 200–400 sq ft per gallon — so run the same formula with the figure printed on your primer can. One coat is the norm for primer.
Why did my room take more paint than the chart says?
Almost always coverage, not arithmetic. Unprimed drywall, heavy texture, and strong color changes all pull real coverage toward 250–300 sq ft per gallon. At 300, every “buy” figure in the chart grows by about a sixth.
Is one gallon ever enough for a whole bedroom?
For one coat in a small room, yes — a 10 × 10 ft room needs 0.91 gallons for one coat. For two coats, even that room crosses into 2 gallons. Bedrooms are two-coat jobs in most cases, which is why 2 gallons is the answer people land on most.
Worked example
For these figures carried through a complete materials budget — paint, primer, tape, and tools — see Cost to Paint a 12×12 Bedroom: Materials & Cost. And if you still need the area itself, our Square Footage Calculator works it out from room dimensions, including L-shaped rooms.
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.