Free Delta-v Calculator

Compute the delta-v available from a rocket stage using the Tsiolkovsky equation: dv = v_e * ln(m0 / mf).

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m/s
kg
kg

Delta-v

6,907.76 m/s

Mass Ratio10.0000

Delta-v vs Effective Exhaust Velocity

View formula & how it works →

The Tsiolkovsky Rocket Equation

dv = v_e * ln(m0 / mf)

  • *v_e* = effective exhaust velocity (or Isp × g0)
  • *m0* = initial mass with propellant
  • *mf* = final mass after burn
  • *ln* = natural logarithm

    • The mass ratio m0/mf determines how much velocity change is possible.

    Example Calculation

    A stage: v_e = 3000 m/s, wet mass 100 000 kg, dry mass 10 000 kg.

    1. 01dv = v_e × ln(m0 / mf)
    2. 02Mass ratio = 100000 / 10000 = 10
    3. 03ln(10) ≈ 2.3026
    4. 04dv = 3000 × 2.3026 ≈ 6 908 m/s

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