Calculate the speed needed to escape a body’s gravity without further propulsion.
Escape velocity is exactly √2 times the circular orbital velocity at the same radius, because escaping requires twice the specific energy of orbiting. It is independent of the escaping object’s mass. Reaching orbit is far cheaper than escaping, which is why almost all missions stage through a parking orbit first.
Escape Velocity
v_esc = √(2 G M ÷ r)
v_esc = √(2 G M ÷ r) Escape velocity is exactly √2 times the circular orbital velocity at the same radius, because escaping requires twice the specific energy of orbiting. It is independent of the escaping object’s mass.
Reaching orbit is far cheaper than escaping, which is why almost all missions stage through a parking orbit first.
This calculator takes 3 inputs: Mass of the body, Radius of the body, Altitude above the surface. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.