Delta-V Calculator (The Rocket Equation)

Delta-V Calculator

Before burn (Rocket mass incl. fuel m1) After burn (Rocket mass excl. fuel m2) Vex or Isp exhaust velocity specific impulse Delta-V change in velocity = Vex*ln(m1/m2)

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Instructions (The Rocket Equation)


Default values show Apollo Lunar Module (LM) ascent stage masses. Ascent stage full mass was 10 300 lbs and dry 5 100 lbs. The rocket engine's specific impulse was 311 s .. and as computed the ascent stage could produce delta-V about 2.144 km/s .. the specifications for LM show delta-V 2.22 km/s .. so the calculation is correct.

Enter full and dry rocket mass in some of the fields above, then press TAB or click Compute.

Mass units are arbitrary; use whatever you like, as long as you're consistent. Similarly, Velocity units are arbitrary; the delta-V computed will be in the same units. Specific impulse is in seconds.

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