Enter the volumetric flow rate (m^3/s) and the density (kg/m^3) into the Calculator. The calculator will evaluate the Mass Flux. 

Mass Flux Formula

MF = VFR * D


  • MF is the Mass Flux (kg/s)
  • VFR is the volumetric flow rate (m^3/s)
  • D is the density (kg/m^3)

To calculate Mass Flux, multiply the volumetric flow rate by the material density.

How to Calculate Mass Flux?

The following steps outline how to calculate the Mass Flux.

  1. First, determine the volumetric flow rate (m^3/s). 
  2. Next, determine the density (kg/m^3). 
  3. Next, gather the formula from above = MF = VFR * D.
  4. Finally, calculate the Mass Flux.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

volumetric flow rate (m^3/s) = 30

density (kg/m^3) = 3.4


What is the difference between mass flow rate and volumetric flow rate?

Mass flow rate measures the amount of mass passing through a cross-section per unit time (kg/s), whereas volumetric flow rate measures the volume of fluid passing through a cross-section per unit time (m^3/s). The mass flow rate accounts for the density of the fluid, while volumetric flow rate does not.

Why is density important in calculating mass flux?

Density (kg/m^3) is crucial in converting volumetric flow rate to mass flow rate because it provides the mass per unit volume of the fluid. By multiplying the volumetric flow rate by the fluid’s density, you obtain the mass flux, representing the mass flow rate through a given area.

How can mass flux be applied in real-world scenarios?

Mass flux has applications in various fields such as chemical engineering, environmental engineering, and mechanical engineering. It is used in designing and optimizing processes like water treatment, air filtration, and fuel combustion systems, where understanding the mass of a substance moving through a system is critical.

Can mass flux vary with changes in temperature or pressure?

Yes, mass flux can vary with changes in temperature or pressure as these factors affect the density of the fluid. For gases, density can significantly change with temperature and pressure, thereby affecting the mass flux. For liquids, the changes are usually less pronounced but can still impact the calculation under certain conditions.