Calculator Inputs
Enter the silo geometry, actual fill height, bulk density, and working utilization. The calculator supports both metric and imperial inputs.
Example Data Table
| Parameter | Example Value | Computed Output |
|---|---|---|
| Material | Cement | Working storage scenario |
| Diameter | 5.50 m | Base radius 2.75 m |
| Straight Wall Height | 14.00 m | Cylindrical shell included |
| Bottom Hopper Height | 2.50 m | Conical hopper included |
| Top Roof Height | 1.50 m | Conical roof included |
| Measured Fill Height | 15.20 m | 88.26% volume fill |
| Bulk Density | 1,440.00 kg/m³ | 416.701 tonnes estimated mass |
| Working Utilization | 90.00% | 289.376 m³ net working volume |
| Total Geometric Volume | — | 364.294 m³ |
| Headspace Remaining | — | 42.765 m³ |
Formula Used
1) Cylindrical Shell Volume
Vcyl = πr²h
2) Full Cone Volume
Vcone = (πr²h) / 3
3) Partially Filled Bottom Hopper
Vhopper,partial = πr²y³ / (3H²), where y is fill depth inside the hopper and H is hopper height.
4) Partially Filled Roof Cone
Vroof,partial = Vroof,total − πr²(H − z)³ / (3H²), where z is fill depth inside the roof cone.
5) Working Volume and Stored Mass
Working Volume = Filled Volume × Utilization / 100
Stored Mass = Working Volume × Bulk Density
This model treats the silo as a conical hopper, cylindrical shell, and conical roof. It is useful for planning storage capacity, inventory checks, and preliminary material estimation.
How to Use This Calculator
- Select metric or imperial input mode.
- Enter the silo diameter and straight wall height.
- Enter hopper height for the bottom cone. Use zero for a flat base.
- Enter roof cone height. Use zero for a flat top.
- Provide the actual fill height measured from the hopper tip upward.
- Enter the bulk density of the stored material.
- Set a utilization factor to reflect safe working capacity.
- Press the calculate button to display result cards, the summary table, and the Plotly graph above the form.
- Use the CSV and PDF buttons to export the latest calculated result.
FAQs
1) What does this silo storage volume calculator estimate?
It estimates total geometric volume, currently filled volume, safe working volume, remaining headspace, and stored material mass for a silo with a conical hopper and conical roof.
2) Why is fill height different from volume percentage?
Volume does not increase evenly through conical sections. A small height increase inside a cone changes volume differently than the same height increase inside the cylindrical shell.
3) What is working utilization?
Working utilization is the usable fraction of the calculated filled volume. It helps reserve free space for safer operations, flow behavior, instrumentation, or operational allowances.
4) Does bulk density affect the volume result?
No. Bulk density does not change geometry-based volume. It only affects the estimated stored mass after the calculator determines the usable material volume.
5) Can I use this for flat-top or flat-bottom silos?
Yes. Set roof height to zero for a flat top, or set hopper height to zero for a flat bottom. The calculator automatically adjusts the volume model.
6) Which units does the calculator support?
It supports metric inputs in meters and kg/m³, plus imperial inputs in feet and lb/ft³. Results are shown in multiple useful volume and mass equivalents.
7) Is this suitable for structural design checks?
No. This tool is for capacity planning and preliminary estimation. Structural design should also consider wall pressure, eccentric loading, material flow, and code requirements.
8) Why does the calculator cap very high fill inputs?
A fill height higher than total silo height is impossible geometrically. The calculator caps it at the maximum internal height and reports the corrected used value.