Escape & Orbital Velocity

How fast must you go to leave a world behind? Escape velocity depends only on a body's mass and radius — 11.2 km/s for Earth, 618 km/s for the Sun.

Escape & Orbital VelocityLive

how fast to leave a world

Escape velocity — Earth

11.19km/s

7.91

orbital km/s

1.00

surface g (× Earth)

Controls

Custom body

Presets

Escape velocity v = √(2GM/R) is the speed needed to break free of a body's gravity from its surface, ignoring air resistance. Circular orbital velocity is √(GM/R) — a factor of √2 smaller. Both depend only on mass and radius, not on the mass of the escaping object.

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Data Inspector

Escape velocity11.19 km/s

Orbital velocity7.91 km/s

Surface gravity9.82 m/s²

Governing equation

v_{e} = \frac{2 GM}{R} = \frac{2 ( 6.674 \times 1 0 ^{- 11} ) ( 5.97 e + 24 )}{6.37 e + 6} = 11.19 km/s

Reading this result: Leaving Earth takes 11.2 km/s no matter the spacecraft mass, while a circular orbit needs only 7.9 km/s — smaller by exactly √2 (about 1.41×).

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How it works

Escape velocity is v = √(2GM/R), the speed at which kinetic energy equals gravitational binding energy from the surface. Circular orbital velocity is √(GM/R), smaller by a factor of √2. Neither depends on the mass of the escaping object. Pick a planet or define a custom mass and radius.

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Frequently asked questions

Is this escape velocity calculator tool really free?▾

Yes. Escape & Orbital Velocity runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.

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The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.