One Wall Paint Calculator
Estimate the paint for a single wall or accent wall from its width and height.
Calculator
Free, runs entirely in your browser, and your numbers never leave your device. Results are estimates for planning only.
What this calculator does
Painting just one wall — an accent wall, a feature wall, or a single repair — does not need a whole-room estimate. This tool takes one wall's width and height, subtracts any door or window, and returns the small amount of paint required.
How to use it
- Enter the wall's width and height (not the whole room).
- Add any door or window on that wall so its area is subtracted.
- Set the coats and coverage, then read the gallons — often a quart will do.
The formula
Wall area = wall width × wall height − openings (each door 21 sq ft, each window 15 sq ft). Paint = area × coats × (1 + waste%) ÷ coverage.
Example calculation
A 14 ft wide, 9 ft tall accent wall with one window, two coats at 350 sq ft/gal, 10% waste:
- Wall area: 14 × 9 = 126 sq ft
- Opening: one window = 15 sq ft
- Paintable: 126 − 15 = 111 sq ft
- Two coats: 222 sq ft, +10% ≈ 244 sq ft
- Paint: 244 ÷ 350 ≈ 0.70 gallons
Result: About 0.7 gallons — a single quart per coat, or one gallon total, is plenty.
Buying and planning tips
- A quart usually covers a single accent wall in two coats, saving money over a gallon.
- For a bold accent color, a tinted primer can cut the number of coats you need.
- Use painter's tape and a level line to keep the accent wall's edges crisp.
Common mistakes to avoid
- Buying a full gallon for a wall that only needs a quart.
- Skipping primer under a dramatic color change, then needing a third coat.
- Measuring the whole room instead of just the one wall.
Assumptions and limits
- Only the single wall you enter is estimated, minus its openings.
- Each door is 21 sq ft and each window 15 sq ft.
- Deep accent colors may need an extra coat or a tinted primer.
Frequently asked questions
How much paint do I need for one wall?
Multiply the wall width by its height, subtract any window or door, apply your coats, and divide by coverage. A 14×9 ft accent wall needs under a gallon — often just a quart per coat.
Is a quart enough for an accent wall?
For most single walls, yes. A quart covers roughly 90–100 sq ft, which is about one coat on an average accent wall.
Do dark accent colors need more coats?
Often. Deep reds, blues, and blacks can need two or three coats; a tinted primer in a similar shade reduces how many topcoats you need.
How do I keep the accent wall edges sharp?
Use quality painter's tape, press the edge down well, and pull it while the paint is still slightly wet for the cleanest line.
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