Using the Pile Cover Storage Dome Calculator

A pile cover storage is a low-profile Monolithic Dome storing a cone-shaped pile of dry bulk product — without storing against the dome wall. Typically the product is conveyed to the top of the dome and poured inside — forming the pile.

This is a reverse dome calculator. Instead of inputting the dome size to calculate storage capacity, you input the target storage capacity and it estimates the size of the dome. This saves a lot of time hunting for the right size dome for a given capacity. Of course, this is just an estimate or ballpark figure meant to begin the design process.

Calculator parameters are stored in the page URL and can be bookmarked, saved, or shared. Use “Copy Link” to share the URL or click “Copy Results” for an email-friendly copy of all results. Print or save the page as a PDF for a professional copy of the drawing and results.

Be aware that just because the calculator can draw a structure, it does NOT mean the structure can be built. This calculator is just a tool. Always consult with qualified professionals before proceeding with a project.

This calculator is subject to our Terms of Service.

Example of small gypsum storage calculation

An example of a small pile cover dome to store 5,000 US tons of gypsum. The total volume of the pile is calculated based on the density of gypsum and target capacity. The angle of repose is then used to calculate cone dimensions necessary to contain the target volume. Then a dome is matched to the cone diameter and height. Click for the live calculator version of this pile cover storage.


Product. Select the product to store in the dome. Product density and angle of repose is determined from the following table.

Product lbs/ft³ g/cm³ angle
Ammonium Nitrate 45 0.72 32°
Coal 55 0.88 27°
Gypsum 75 1.20 35°
Oats 26 0.42 21°
Phosphate 60 0.96 26°
Potash 80 1.28 40°
Rice 45 0.72 20°
Rock Salt 78 1.25 33°
Rye 45 0.72 23°
Sand 100 1.60 33°
Salt 75 1.20 25°
Sorgum Seed 50 0.80 31°
Soybeans 45 0.72 25°
Urea 47 0.75 32°
Wheat 45 0.72 28°

Capacity. The target capacity for the stored product.

Weight. The target capacity unit of measure — select pounds (lbs), US tons (ton), kilograms (kg), or metric tonnes (tonne).

Overlay. A scaled, graphical overlay to assist in visually representing the building size and purpose. We recommend the “loader” for a storage dome.

Units. Select the target output unit of measure. Input capacity to output units of measure is automatic and cross-compatible — pounds to meters, tonnes to feet, etc.

Product Output

Product Density. The US or metric density of the named product determined by the product table and the output unit of measure.

Angle of Repose. When pouring the product into a pile it naturally forms a cone with a slant angle based on the product characteristics.

Storage Capacity. The target storage capacity input into the calculator.

Product Cone

Radius. The radius at the base of the calculated product pile cone.

Height. The height of the calculated product pile cone.

Slant Length. The length down the side of the pile cone.

Surface Area. The lateral surface area of the product pile cone.

Pile Volume. The calculated volume in the output unit of measure based on the input capacity.


Diameter. The floor diameter is a circle representing the floor, pile cone, and dome base diameter.

Radius. The floor radius is half the floor diameter and is a useful number for various calculations.

Circumference. The floor circumference is the distance around the circle-shaped floor, pile cone, and dome base.

Area. The floor area is the area of the circle inscribed by the floor diameter.


Height. The dome height is the distance from the base of the dome to the apex.

Radius of Curvature. All dome structures described by this calculator are a segment or “cap” of a sphere as defined by the dome’s diameter and height. The radius of curvature is the calculated radius of the whole sphere of which the dome is a portion.

Surface Distance. The dome surface distance is the length from the apex, following the dome curve down to the dome base.

Surface Area. The dome surface area is technically the dome’s lateral surface area from the base to the apex.

Volume. The dome volume is the cubic measure of the volume encompassed by the structure’s dome portion.


An overlay is a scaled illustration to help convey the size, purpose, and scope of the calculated structure. They are for convenience only. No attempt is made to “fit” them inside the building or to determine their appropriate use for a structure. They are merely a visual aid.

None. The none overlay deletes the overlay.

Person. The person overlay is the default overlay. It is a person rendered at 6-feet (1.8 m) tall.

Car. The car overlay is a mid-sized sedan with a 6-foot (1.8 m) person standing beside it.

BBall. The bball overlay is the side silhouette of a standard American competition basketball court on a six-inch floor. We recommend setting the level parameter to 20.5 feet to show the standard clearance height required for a competition floor.

Loader. The loader overlay is a small front-end loader approximately 100 inches (2.5 m) tall next to a 6-foot (1.8 m) tall person.

Example of lower angle of repose salt storage dome calculation

The lower angle of repose for salt creates a much lower profile dome to store the 2,000 metric tonnes demonstrated in the drawing. Click for the live calculator version of this pile cover storage.