Tank Volume Calculator
Vertical cylinder, horizontal cylinder with a circular segment fill, or a rectangular box. Output is m³, liters, and US gallons. The manufacturer stamp wins. This is not a pool-volume calculator.
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How to estimate tank volume
- Pick vertical cylinder, horizontal cylinder, or rectangle, then pick the length unit.
- Vertical needs radius and height. Horizontal needs radius and length. Rectangle needs length, width, and height.
- Optional: type a fill height for a partial vertical or horizontal tank. Blank means full.
- Read m³, liters, and US gallons. Trust the stamped capacity if it disagrees. Not a pool calculator.
Tank capacity
Cylinder or box, optional partial fill
| Vertical | π r² h, or π r² × fill |
|---|---|
| Horizontal fill | Circular segment area × length |
| Rectangle | L × W × H |
| Liters | m³ × 1000 |
| US gallons | m³ / 0.003785411784 |
| Advice | Estimate only. Manufacturer stamp wins. Not a pool-volume page. |
How tank volume is computed
Sizes convert to meters. A vertical tank is π r² times height, or times fill if you set fill. A full horizontal tank is π r² times length. A partial horizontal uses a circular segment. A rectangle is the product of three edges. Liters and US gallons follow from m³.
Cylinder tank, gallons, and the stamp
US gallons use 3.785411784 L. A dedicated liter converter is liters to gallons. Geometric volume without tank shapes is the volume converter. A concrete cylinder pour is concrete.
Not a pool calculator
Pools, freeform spas, and irregular basins are out of scope. Heads, dishes, and saddles are not modeled. Estimate only. The nameplate on the tank wins.
Use cases
A standing water tank, a horizontal shop tank with a liquid height, or a rectangular cistern. Pressure vessels need an engineer, not this page.
Limits
Fill cannot exceed height (vertical) or diameter (horizontal). Required sizes must be greater than 0. Not code approval. CZNull does not receive the numbers.