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Tsiolkovsky Rocket Equation Calculator

Find ideal Δv = ve ln(m₀ / m_f) for a rocket with no gravity or drag losses.

 

 

 

Δv (m/s)

About this calculator

Use this calculator for the Tsiolkovsky rocket equation: Δv = ve ln(m₀ / m_f). ve is effective exhaust speed (Isp × g0). m₀ is wet mass at ignition, m_f after burnout.

A 4:1 mass ratio with ve = 3000 m/s gives about 4.2 km/s. Wet mass must be greater than dry mass. Gravity and drag losses are extra on a real launch; staging is several burns in a row.

Exhaust speed (m/s): Effective exhaust velocity, in metres per second.

Wet mass (kg): Mass including propellant, in kilograms.

Dry mass (kg): Mass after the burn, still positive and less than wet.

Δv (m/s): Ideal change of speed in vacuum, no losses.