Paint Calculator
Calculates how many gallons of paint you need from the wall area in square feet, the number of coats, and the paint coverage in square feet per gallon. It multiplies area by coats and divides by coverage.
What this calculator does
The Paint Calculator estimates your result instantly from the values you enter, using standard construction & home formulas. Calculates how many gallons of paint you need from the wall area in square feet, the number of coats, and the paint coverage in square feet per gallon. It multiplies area by coats and divides by coverage. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Paint Calculator
This paint calculator estimates the gallons needed for a job. It multiplies the wall area by the number of coats, then divides by the coverage rating of your paint in square feet per gallon.
Formula & Mathematical Calculation
Paint Needed (gal) = f(Wall Area (ft²), Coats, Coverage (ft²/gal))
Calculated according to standard construction formulas implemented in the calculator core.
Calculation Example
To paint 400 ft² with 2 coats using paint rated at 350 ft²/gal:
- Gallons = 400 × 2 ÷ 350 ≈ 2.29 gal
Key Benefits
- Accounts for multiple coats, not just a single pass
- Uses your paint's own coverage rating for a realistic gallon estimate
- Gives the result as a decimal gallon figure you can round up when buying
- Keeps the calculation to three simple inputs
How to Use this Calculator
-
Enter the wall area
Type the area to paint in square feet into the Wall Area (ft2) field, for example 400. -
Enter the number of coats
Type how many coats you plan to apply into the Coats field, for example 2. -
Enter the coverage
Type the paint's coverage in square feet per gallon into the Coverage (ft2/gal) field, for example 350. -
Calculate
Press Calculate to see how many gallons of paint you need.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Paint Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.