Enter the dimensions of the silo cylinder and the cone hopper beneath it to get the volume of each section and the total, then apply the bulk density and fill ratio of the stored solid to obtain the mass it actually holds. All diameters are inside diameters.
The cylinder volume comes from its diameter and height, while the hopper uses the frustum formula because its top and outlet diameters differ. Both are geometric definitions, so no reference document is involved, and the two section volumes are reported separately so you can verify which formula produced what. Figures current as of October 2026.
Bulk densities, fill ratios and angles of repose for specific solids are not confirmed by an authoritative source, so none are offered and you enter your own, taken from supplier data or site measurement. The hopper wall angle is reported purely as geometry and does not judge whether the material will discharge without bridging. Structural checks and discharge rate sizing are not covered. This calculator is for reference and does not replace design. Review by a qualified engineer is required.
Frequently Asked Questions
It depends on the solid and on how the silo discharges, and no authoritative figure is confirmed, so none is offered here. Use the value from your equipment supplier or a measurement from the installation.
Yes. The hopper is handled with the frustum volume formula, so the top and outlet diameters are taken separately. The outlet diameter has to be smaller than the top diameter, and the calculation stops with a notice if it is not.
It is the wall angle from horizontal implied by the hopper height and the difference between the top and outlet radii. It is a geometric figure only and does not judge whether the solid will flow.