Mechanical & Civil Engineering
Tsiolkovsky Rocket Equation Calculator
Calculate the change in velocity (delta-v) a rocket can achieve based on specific impulse and mass ratio.
Your inputs
Change any value to update the result instantly.
Delta-v
2,695.7 m/s
Mass ratio
2.5
Propellant mass
6,000 kg
Effective exhaust velocity
2,942 m/s
Delta-v in km/s
2.696 km/s
What this calculator does
Tsiolkovsky Rocket Equation Calculator: Applies the standard aerodynamics or orbital-mechanics relationship so the force, efficiency or manoeuvre cost can be worked out from the flight inputs.
What your result means
The headline figure is the aerodynamic force, efficiency or manoeuvre cost implied by your flight inputs. Real vehicles carry additional losses and margins.
Formula and working
Δv = Isp·g0·ln(m0/mf)
- 1
Collect the inputs
Specific impulse = 300 s; Initial mass (wet) = 10,000 kg; Final mass (dry) = 4,000 kg
- 2
Apply the formula
Δv = Isp·g0·ln(m0/mf)
- 3
Result
Delta-v = 2,695.7 m/s
Frequently asked questions
Symbols and assumptions
- Isp
- Specific impulse (s)
- m0
- Initial mass (wet) (kg)
- mf
- Final mass (dry) (kg)
- • Standard-atmosphere and idealised flow or two-body orbital conditions are assumed.
- • Losses, gravity turn, atmospheric drag and vehicle-specific effects are not modelled unless the page names them.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • This is an educational estimate for learning and checking, not a design deliverable.
- • Real design must follow the governing code or standard for your jurisdiction and be reviewed and signed off by a qualified engineer.
- • Safety factors, load combinations and material certification are the responsibility of the designer, not of this page.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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