Escape Velocity Calculator
Enter a body's mass and radius, or pick a preset planet, to find the escape velocity: the minimum speed needed to break free of its gravity without further thrust.
How to use the escape velocity calculator
- Pick a planet preset or enter the body's mass in kilograms.
- Enter the radius in metres (the launch distance from the centre).
- Read the escape velocity in metres and kilometres per second.
Examples
Escape velocity from Earth
mass = 5.972e24 kg, radius = 6.371e6 m
v = 11.19 km/s
Escape velocity from the Moon
mass = 7.342e22 kg, radius = 1.7374e6 m
v = 2.38 km/s
Frequently asked questions
What is escape velocity?
Escape velocity is the minimum launch speed an object needs to break free from a body's gravity and never fall back, ignoring air drag and further propulsion.
What is the escape velocity formula?
v = sqrt(2 x G x M / r), where G is the gravitational constant, M is the body's mass and r is the distance from its centre, usually its radius.
What is Earth's escape velocity?
About 11.19 km/s, or roughly 11,186 m/s, from Earth's surface. The Moon is much lower at about 2.38 km/s because it has far less mass.
Does escape velocity depend on the launched object's mass?
No. The object's own mass cancels out of the equation, so a pebble and a rocket need the same escape speed from the same point.
Does escape velocity depend on launch direction?
No, not in this idealised form. It is a speed, not a velocity vector, so any direction that clears the surface needs the same magnitude.
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