Rocket Equation Calculator
Calculate rocket performance using the Tsiolkovsky rocket equation. This equation relates the change in velocity (Δv) with the effective exhaust velocity (ve) or specific impulse (Isp) and the mass ratio of the rocket.
s
The Rocket Equation
Δv = ve × ln(m0/mf)
Also known as the Tsiolkovsky Rocket Equation
Where:
- ΔvDelta-v: maximum change in velocity that the rocket can achieve
- veEffective exhaust velocity of the propellant (ve = Isp × g0)
- IspSpecific impulse of the propellant
- g0Standard gravity at Earth's surface (9.80665 m/s²)
- m0Initial total mass, including propellant
- mfFinal total mass without propellant
- lnNatural logarithm
Key Concepts:
- The rocket equation demonstrates that achieving higher delta-v requires either higher exhaust velocity (better propellant) or a higher mass ratio.
- Mass ratio is limited by structural requirements - a rocket needs structure to hold the propellant.
- Specific impulse is a measure of propellant efficiency - higher values mean more efficient propellant.
- For chemical rockets, typical specific impulse values range from ~250-450 seconds.
- For ion/electric propulsion, specific impulse can exceed 3000 seconds.
Multi-stage Rockets
Multi-stage rockets improve delta-v by discarding empty tanks and engines as propellant is used. The total delta-v of a multi-stage rocket is the sum of the delta-v of each stage.
Open Source & Transparent
This tool is open source and the underlying logic is fully transparent. You can view the source code, understand the calculations, and even contribute improvements to make it better for everyone.
View Source Code