Created By : Naaz Fatima

Reviewed By : Rajashekhar Valipishetty

Last Updated : Apr 10, 2023

Rocket Equation Calculator is a free tool that provides the change in velocity if you give input paramters exhaust velocity, initial, final mass of the rockets, etc. This free tool will make your calculations much simpler and produces the results in the blink of an eye.

Choose a Calculation
Effective exhaust velocity
Initial mass
Final mass:

What is meant by Rocket Equation?

Rocket Equation describes the motion of a device that applies acceleration to themselves using thrust. It describes the relationship between velocity of rocket, exhaust velocity, mass. We can use the Rocket Equation in simple cases when no other external forces act on it.

How to find Change in Velocity?

Follow the simple guidelines provided below to determine the change in velocity using Rocket Equation. They are as such

  • Firstly, determine the exhaust velocity, initial mass, final mass.
  • Then, simply input the known parameters in the formula to find the change in velocity i.e. ╬öv = ve * ln(m0 / mf).
  • On simplification you will get the change in velocity.

Rocket Equation Formula

Velocity of Rocket can be found using the formula

Δv = ve * ln(m0 / mf)

In which Δv stands for Change of Velocity

ve is effective exhaust velocity

m0 is the initial mass including rocket weight and propellants

mf is the final mass including rocket weight without propellants

Δv is the difference between final and initial velocity

Greater the ve and m0 the higher velocities you can get.


If the effective exhaust velocity is 5,400 km/h, initial mass is 45 t, final mass is 20 t calculate the change in velocity?


Given that

Effective Exhaust Velocity = 5,400 km

Initial Mass = 45 t

Final Mass = 20 t

We know formula for Change in Velocity Δv = ve * ln(m0 / mf)

Substitute the input values in the formula Δv = 5400 * ln(45 / 20)

On simplification we get change in velocity Δv = 1.2164 km/s

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Multistage Rocket Equation Formula

During the motion of the rocket many parts are rejected one after the other. For suppose a part runs out of fuel it becomes redundant mass and needs to be removed. Change of velocity can be found independently for every step and then linearly sum up Δv = Δv1 + Δv2 + .... One Advantage of using this is we can employ a different type of rocket engine tuned for different conditions.

Frequently Asked Questions on Rocket Equation Calculator

1. How do you calculate delta V for a rocket?

You can calculate the delta v or change in velocity by using the formula Δv = ve * ln(m0 / mf).

2. Who invented the Rocket Equation?

Russian Scientist Konstantin Tsiolkovsky invented the rocket equation in the year 1903.

3. Why Tsiolkovsky rocket equation is called an ideal rocket equation?

Tsiolkovsky rocket equation can be used in simpler cases i.e. when no external forces act on the rocket. Therefore, it is called an ideal rocket equation or classical rocket equation.

4. What does the Rocket Equation Tell Us?

Rocket Equation is a mathematical equation that describes the motion of vehicles following rocket principle i.e. devices that can accelerate themself using thrust.