WaterCalcLabWater Tank Volume Calculator
Calculate exact geometry from internal dimensions for a vertical cylinder, box or sphere.
Your result
Bars compare only results in the same unit group. They are normalized, not a time-series forecast.
Planning result based on your inputs.
How this tool works
Calculate exact geometry from internal dimensions for a vertical cylinder, box or sphere.
cylinder: πr²h; box: LWh; sphere: 4πr³/3 (m³ × 1000 = L)Example calculation
The prefilled form is a worked example. Its base-unit inputs and expected outputs are shown below; use the reset button to restore it.
| Input | Example |
|---|---|
| Tank geometry | Vertical cylinder |
| Internal radius | 1 |
| Height / water depth | 2 |
| Horizontal length | 10 |
| Horizontal width | 8 |
Frequently asked questions
How should I choose the inputs?
Use measurements and local records for the stated period. All preset values are illustrative examples, not recommendations.
What does this result leave out?
Use internal dimensions; rounded corners, dead storage and freeboard reduce usable volume. This is not structural or pressure-vessel design.
Continue your plan
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Open calculator ↗Related reading
Water storageHow to Calculate Tank Capacity
Geometry tells you the volume inside a shape. Sizing asks whether that volume matches supply and demand. Establish which question you need to solve. A correctly calculated cylinder volume can still be an unsuitable garden supply. Conversely, an appropriate capacity target needs product dimensions and operating levels to confirm how much water can actually be stored.
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Write a short specification describing the uses, required usable volume, outlet flow, installation space and maintenance access. A tank is one component of a system, so compare options against the same specification. A bigger container is not automatically better if it cannot be filled regularly, is difficult to service or needs a costly pump arrangement.
Read guide ↗Sources & method references
Method version 1.0 · Last reviewed: 2026-10-10