Circular shell
V = πR²H
Volume of the cylindrical section.
Existing engineering calculator
Silo & Bunker Sizing Calculator
Estimate circular silo or rectangular bunker storage volume, hopper volume and effective capacity.
Calculator inputs and result
Select a storage type and enter the existing calculator inputs in millimetres and degrees.
Circular silo inputs
A preset fills the existing angle-of-repose input. Confirm the actual material value for moisture, particle size and handling conditions.
Rectangular bunker inputs
Engineering knowledge
Storage geometry and usable bulk-material capacity
Geometric volume is the enclosed space in a silo or bunker. Usable capacity can be lower because of material slopes, discharge geometry, operating level limits and the properties of the stored bulk solid.
Related calculation knowledge
Check material bulk density, flow properties, outlet design and live storage requirements alongside volume.
Explore bulk-material handling →What the calculator reports
Conical-frustum hopper
h = (R − r) tan α
Angle α is measured from horizontal. Hopper volume is V = πh(R² + Rr + r²) / 3.
Rectangular bunker
V = L × W × H
The existing model adds the simplified hopper volume separately.
Assumptions and limitations
- This calculator is for preliminary geometric capacity checks only.
- It does not verify wall loads, hopper stresses, feeder capacity, bridging, ratholing or discharge reliability.
- Use representative bulk density and specialist solids-flow design methods for project decisions.
Frequently asked questions
Is water volume the same as material storage mass?
No. Multiply a usable volume by the material bulk density only after considering moisture, compaction and operational freeboard.
Why can effective capacity be lower?
A material heap and the required operating freeboard occupy space that cannot normally be treated as working storage.
Engineering disclaimer
Educational and preliminary engineering-reference use only.Verify material behaviour, design loads, geometry and applicable standards before equipment design or procurement.