Size elevated tanks fast for accurate capacity planning. Add bottom frustums and domes when needed. Export clear results to share with every stakeholder today.
Example inputs for a cylindrical elevated tank with a frustum bottom and no roof storage.
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Tank Type | Cylindrical | - | Main shell stores water |
| Diameter | 6.5 | m | Internal diameter |
| Shell Height | 8.0 | m | Water column in shell |
| Bottom Type | Frustum | - | Hopper style bottom |
| Bottom Height | 1.2 | m | Vertical height |
| Bottom Small Diameter | 1.0 | m | Outlet diameter |
| Freeboard | 5 | % | Operational allowance |
| Water Density | 1000 | kg/m³ | Fresh water |
V = π × (D/2)² × HV = (π × h / 3) × (r₁² + r₁r₂ + r₂²)V = (2/3) × π × r³V = L × W × HVnet = Vgross × (1 − freeboard%/100)W(kN) = (ρ × Vnet × g) / 1000Elevated storage is typically sized from demand and firefighting requirements, then verified against geometry. A small dimensional change can shift capacity significantly. For example, a 6.0 m diameter cylinder gains about 28.3 m³ for every 1.0 m increase in water height (≈ 28,300 L). Using consistent units and verified dimensions reduces rework during detailing and procurement. It also improves bid leveling and lifecycle cost comparisons.
The cylindrical shell usually provides the primary storage. Cone and frustum bottoms add measurable volume while improving drainage, sludge control, and outlet hydraulics. A hemispherical dome is often treated as non-storage, but it can be included if the operating level reaches into the dome. This calculator separates each component so assumptions remain transparent.
Freeboard protects against overflow, wave action, and operational uncertainty. Many designs apply 2%–10%
freeboard depending on control strategy and inflow variability. The calculator converts gross geometry into a net operating volume
using Vnet = Vgross × (1 − freeboard/100), helping align storage with real deliverable water.
Project documentation often mixes units. This tool reports cubic meters and converts to liters and US gallons for tender schedules and O&M manuals. Quick conversion checks also help validate whether capacity targets such as 100,000 L (100 m³) are being met after freeboard is applied. For audits, note whether dimensions are internal, nominal, or adjusted for lining, because that choice can change reported capacity.
Stored water governs vertical loading on the staging and foundation. With a density near 1000 kg/m³, each 1 m³ of water weighs about 9.81 kN. By estimating net water weight in kN, the calculator supports early checks for column sizing, bracing, and bearing pressure before detailed structural modeling.
Gross volume is the geometric capacity from the entered shapes. Net operating volume subtracts the freeboard allowance, representing usable storage under normal operation.
Only include it if your operating water level rises into the dome. Many tanks treat domes as non-storage for ventilation and access, so leaving it excluded is common.
Select cone or frustum bottom and enter bottom height. For a frustum, also enter the small diameter at the outlet. The tool adds this volume below the shell.
Many projects use 2% to 10% depending on controls, inflow variability, and overflow protection. Use your local standard or client specification if available.
Yes for volume, because geometry is the same. For weight, update the density to match your liquid. Confirm material compatibility and safety requirements separately.
kN is convenient for structural checks. It converts mass to force using gravity and helps estimate column and foundation demand during early design.
Diameter (or plan dimensions) and water height dominate, because volume scales with area. Freeboard then reduces usable capacity, so it can materially change deliverable storage.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.