Created By : Vaibhavi Kumari

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 23, 2023

To calculate the delta-v of a rocket, Discover a little bit about spacecraft flight dynamics with our delta-v calculator. Moving in space is very different from moving on the surface of a planet. How fast can you go up there? You might need to know what delta-v is if you're studying orbital manoeuvres or playing Kerbal Space Program. To find out, continue reading:

I want to calculate
Specific impulse (Iₛₚ)
Initial mass (m₀)
Final mass (mₜ)
Delta-v (Δv)

What is “Delta-V” ?

The term "delta-v" (or "Delta vΔv") refers to the difference in velocity between two points. This quantity is commonly found in physics, and it is especially important when moving in space, such as between orbits, bodies, or just arbitrary points.

There is no friction in space because there is no air resistance. There's nothing you can do to slow down your starship once it reaches a certain speed; you can only coast till the users reach your destination, at which point you must brake or risk overshooting! The concept of distance is thus irrelevant: it only matters to humanity since it means we must wait for our probe to reach Neptune's icy moons, or because we are bored waiting to land on Mars.

When making plans for your space trip, consider the amount of propellant needed to get to your destination rather than the distance travelled. Identify the nature of the engine in use, this quantity easily translates to the difference in speed that can be achieved while travelling.

How do I find out the delta-v ?

The rocket equation can be used to calculate the delta-v: either as the specific impulse or the effective exhaust speed can be used in the calculations. The formula is as follows:

Δv = Iₛₚ * g₀* ln(m₀/mₜ) = vₑ * ln(m₀/mₜ)


  • v = change in velocity of the rocket (m/s)
  • Ve = exhaust velocity (m/s)
  • mi = initial mass of the rocket (kg)
  • mf = final mass of the rocket (kg)

How do I use our delta-v calculator ?

It's very simple to use our delta-v calculator. 

  • Step 1: Insert the specific impulse or the exhaust speed first.
  • Step 2: Fill in the remaining fields, including the initial and final mass. Make sure you write them in the right order!
  • Step 3: Finally got the answer.

To enter Earth's orbit, how much delta-v is required ?

The delta-v required to achieve Earth's orbit varies depending on the type of orbit, the launch location, and a variety of other factors, but it typically begins at around 9 km/s. The achieved orbital speed must be reduced by a fraction of the velocity lost.

Get similar concepts of physics all under one roof explained clearly with step by step process on a trusted portal for all your needs.

FAQs on Delta-V Calculator

1. What is meant by delta-v?

Delta-V (v) is a common notation for a change or difference in velocity that is used in mathematics and physics. The change in velocity between a vehicle's pre-collision and post-collision trajectories is referred to as v in the context of a motor vehicle crash.

2. How to find out delta-v for a car accident?

The total change in vehicle velocity per unit the duration of the crash event is simply defined as Delta-V, the long-standing metric of crash severity. Delta-V is traditionally calculated using crash reconstruction techniques, such as "crunching numbers" by hand or with computer codes.

3. Is delta-v always in the positive direction?

It's always positive (you can't "unapply" pressure or impart "negative energy"), and in pressure-volume work, the external pressure is usually constant while the internal pressure varies.

4. What is delta-v Delta?

The acceleration is defined as the ratio of delta-v/delta-t. This ratio represents the average acceleration if the acceleration is not constant and the time interval is finite. The velocity-time graph's slope is called acceleration.

5. Is Delta va considered a vector?

The thrust of a rocket engine typically provides a delta-v. The actual acceleration vector is calculated by multiplying the gravity vector by the thrust per kilogramme vector. Without gravity, delta-v is simply the change in speed in the direction of the velocity in the case of thrust in that direction.