Enter the mass flow rate, thrust, exit pressure, atmospheric pressure, and area into the calculator to determine the exhaust velocity.

Exhaust Velocity Formula

The following equation is used to calculate the Exhaust Velocity.

V = (F – (pe-pa)*A)/mdot

  • Where V is the exhaust velocity (m/s)
  • F is the thrust force (N)
  • pe is the exit pressure (N/m^2)
  • pa is the atmospheric pressure (N/m^2)
  • A is the exhaust area (m^2)
  • mdot is the mass flow rate (kg/s)

What is an Exhaust Velocity?


An exhaust velocity describes the linear flow rate of exhaust gas out of the end of a rocket.

How to Calculate Exhaust Velocity?

Example Problem:

The following example outlines the steps and information needed to calculate Exhaust Velocity.

First, determine the thrust force. In this example, the thrust force is found to be 5000 N.

Next, determine the exit pressure. For this problem, the exit pressure is found to be 100 N/m^2.

Next, determine the atmospheric pressure. In this case, the atmospheric pressure is measured to be 25 N/m^2.

Next, determine the exhaust area. This is found to be 2.5m^2.

Next, determine the mass flow rate. This is found to be 500 kg/s.

Finally, calculate the Exhaust Velocity using the formula above:

V = (F – (pe-pa)*A)/mdot

V = (5000 – (100-25)*2.5)/500

V = 9.625 m/s