Tank Capacity Calculator
Enter tank diameter and height or length and this tank capacity calculator returns the cylinder volume in cubic feet and gallons. Note: the Orientation dropdown does not change the result; volume is always computed as a full cylinder.
What this calculator does
The Tank Capacity Calculator estimates your result instantly from the values you enter, using standard construction & home formulas. Enter tank diameter and height or length and this tank capacity calculator returns the cylinder volume in cubic feet and gallons. Note: the Orientation dropdown does not change the result; volume is always computed as a full cylinder. 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 Tank Capacity Calculator
The Tank Capacity Calculator computes the volume of a cylindrical tank from its diameter and height or length, reporting both cubic feet and gallons. Note: although an Orientation dropdown is shown, the shipped calculation always uses the full-cylinder formula, so vertical and horizontal give the same answer.
Formula & Mathematical Calculation
Volume (ft³) = f(Tank Diameter (ft), Tank Height/Length (ft), Orientation)
Calculated according to standard construction formulas implemented in the calculator core.
Calculation Example
For a tank with a diameter of 4 ft and a height/length of 6 ft, the tool computes pi x (4/2)² x 6 = 75.4 cubic feet, then multiplies by 7.48052 gallons per cubic foot. The Volume (ft³) box shows 75.4 and the Capacity (gallons) box shows 564 gal.
Key Benefits
- Computes cylinder volume in cubic feet from diameter and height
- Converts the volume to gallons at 7.48052 gallons per cubic foot
- Rounds volume to two decimals and gallons to one decimal
How to Use this Calculator
-
Enter the diameter
Type the Tank Diameter (ft). -
Enter the height or length
Type the Tank Height/Length (ft). You can pick an Orientation, though it does not change the result. -
Calculate
Click Calculate to read the Volume (ft³) and Capacity (gallons) boxes.
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
- Tank Capacity 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.