Enter the diameter, pitch, rpm, loading ratio, material loose density, and inclination factor into the calculator to determine the screw conveyor flow rate, also known as the capacity.

Screw Conveyor Flow Rate Formula

The following equation is used to calculate the Screw Conveyor Flow Rate.

Q = 60 * pi/4 * D^2 * S * N * a * d * C

  • Where Q is the mass flow rate (kg/hr)
  • D is the diameter of the screw (m)
  • S is the screw pitch (m)
  • N is the RPM
  • a is the loading ratio
  • d is the loose material density (kg/m^3)
  • C is the inclination factor

In this case, the units of measure of meters can be substituted for feet, inches or other, as long as the material density provided is then in the matching units.

What is a Screw Conveyor Flow Rate?


A screw conveyor flow rate, also sometimes considered the capacity, is a measure of the total mass the conveyor can move per unit of time.

How to Calculate Screw Conveyor Flow Rate?

Example Problem:

The following example outlines the steps and information needed to calculate Screw Conveyor Flow Rate.

First, determine the diameter. In this example, the conveyor diameter is 1m.

Next, determine the conveyor pitch. This conveyor has a pitch of .35m.

Next, determine the rotational speed. This rotational speed is measured to be 50 RPM.

Next, determine the load ration. This conveyor is specified at a loading ratio of 1.25.

Next, determine the material density. This material has a density of 150 kg/m^3.

Next, determine the inclination factor. There is not inclination in this example, the this factor is 1.

Finally, calculate the conveyor screw flow rate using the formula above:

Q = 60 * pi/4 * D^2 * S * N * a * d * C

Q = 60 *3.14159/4 * 1^2 * .35 * 50* 1.25 * 150 * 1

Q = 154,625.13 kg/hr