Enter the rock mass (lbs) and the rock volume (ft^3) into the Rock Density Calculator. The calculator will evaluate and display the Rock Density. 

Rock Density Formula

The following formula is used to calculate the Rock Density. 

RD = RM / RV
  • Where RD is the Rock Density (lbs/ft^3)
  • RM is the rock mass (lbs) 
  • RV is the rock volume (ft^3) 

To calculate the rock density, divide the rock mass by the rock volume.

How to Calculate Rock Density?

The following example problems outline how to calculate Rock Density.

Example Problem #1:

  1. First, determine the rock mass (lbs).
    1. The rock mass (lbs) is given as: 90.
  2. Next, determine the rock volume (ft^3).
    1. The rock volume (ft^3) is provided as: 3.
  3. Finally, calculate the Rock Density using the equation above: 

RD = RM / RV

The values given above are inserted into the equation below:

RD = 90 / 3 = 30 (lbs/ft^3)


Example Problem #2: 

For this problem, the variables needed are provided below:

rock mass (lbs) = 145

rock volume (ft^3) = 34

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer. 

RD = RM / RV = ?