Escape Velocity Calculator — v = √(2GM/r)

Escape velocity is √2 times the circular orbital speed at the same radius — the kinetic energy must overcome the full gravitational potential well. G is built in.

Escape Velocity Calculator — v = √(2GM/r)

$v_e = \sqrt{\frac{2GM}{r}}$

Solve for

Escape velocity (vₑ)

Unit

Body radius (r)

Unit

Result unit

How to interpret the result

Earth's escape velocity is 11.2 km/s — which is why rockets need staging and huge fuel fractions to leave for the Moon or Mars.

Assumptions

Launch from the body's surface (radius = body radius)
No atmosphere or air drag
Non-relativistic speeds