Free Escape Velocity Calculator

Calculate the minimum speed needed to escape a celestial body's gravitational pull using v_esc = sqrt(2 G M / r).

kg
m

Escape Velocity

11,185.73 m/s

Escape Velocity (km/s)11.1857 km/s

Escape Velocity vs Body Mass

Deriving Escape Velocity

Escape velocity is the minimum launch speed at the surface for an object to reach infinity without further propulsion.

Formula

v_esc = √(2 G M / r)

This is exactly √2 times the circular orbital velocity at the same radius. It comes from setting kinetic energy equal to gravitational potential energy: 1/2 m v² = G M m / r.

Example Calculation

Find Earth's escape velocity (M = 5.972e24 kg, r = 6 371 km).

  1. 01v_esc = √(2 G M / r)
  2. 022 G M = 2 × 6.674e-11 × 5.972e24 = 7.972e14
  3. 037.972e14 / 6.371e6 = 1.251e8
  4. 04v_esc = √(1.251e8) ≈ 11 186 m/s ≈ 11.19 km/s

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