The Pyramid Frustum Weight (Mass) formula computes the weight or mass of a right square pyramid with a frustum defined by base side length (R) and top side length (r) and height (h) in between and a mean density (mD).
INSTRUCTIONS: Choose units and enter the following:
Pyramid Frustum Mass/Weight (M):The mass is calculated and returned in kilograms. However, the user can automatically convert this to any of the other mass/weight units (e.g. pounds, tons) via the pulldown menu.
This formula computes the volume of the geometric shape based on the input parameters. With the computed volume, this formula then executes the simple equation below to compute the approximate mass of the object.
A Right Square Pyramid has a four sided base where all four sides are equal and have equal angled corners (90^{o}), which is a square. The pyramid is a right pyramid if the apex of the pyramid is directly above the center of the base square. The formula for the volume of a pyramid with a triangle base is:
`M = 1/3 * h*(R^2+R * r+r^2) * mD`
where:
Common Mean Densities in Kilograms per Meter Cubed (kg/m^{3})  
Fluids
Fuels
MarketReady Grains 
Metals

Earthen
Synthetic
Organic

Mean Density Lookup Function 
Mean density is scientifically volume divided by mass. There are various unit for density adopted by cultures and industries. Common units for density included the following: