Escape Velocity (any body) Calculator
Escape velocity is the minimum speed an object needs to break free of a body's gravity without any further push, coasting away forever rather than falling back. It is a single number that captures how deep a planet, moon or star's gravity well is, and it depends only on two things: how much mass the body has and how far you start from its center. This calculator works for any body, not just Earth. You enter the central mass and the radius at which you are launching, and it returns the escape velocity using the standard gravitation formula. The result is the speed at which the object's kinetic energy exactly balances the gravitational potential energy holding it down, so anything faster will escape. Notice that the escaping object's own mass never appears: a grain of dust and a rocket need the same escape speed from the same place, though the rocket needs far more energy to reach it. The defaults describe Earth at its surface, giving the familiar figure of about 11.19 kilometers per second. Every figure here is computed deterministically from the standard physics formula shown below, with a worked example that reconciles exactly to the calculator defaults so you can check each step yourself.
Escape velocity equals the square root of two times the gravitational constant times the central mass, divided by the radius: v = sqrt(2 x G x M / r), with G fixed at 6.674e-11. For a mass of 5.972e24 kg and a radius of 6.371e6 m (Earth's surface), the escape velocity is 11,185.73 m/s, about 11.19 km/s.
Escape velocity formula
v = sqrt(2 x G x M / r)
G = 6.674e-11 N m^2/kg^2 (fixed constant)
M = central body mass (kg)
r = radius from the center at launch (m)
v = escape velocity (m/s)
The escaping object's mass does not appear, so escape velocity is a property of the central body and the launch radius alone. Larger mass raises the escape speed; launching from farther out, where r is larger, lowers it.
Worked example
Take Earth's surface: a central mass of 5.972e24 kilograms and a radius of 6.371e6 meters, with G fixed at 6.674e-11.
- 2 x G x M = 2 x 6.674e-11 x 5.972e24 = 7.972e14
- Divide by r: 7.972e14 / 6.371e6 = 1.2513e8
- v = sqrt(1.2513e8) = 11,185.73 m/s
The escape velocity is 11,185.73 m/s, about 11.19 km/s. These are the calculator's default inputs, so the result above matches the widget exactly.
Escape velocity of selected bodies
| Body | Mass (kg) | Approx. escape velocity |
|---|---|---|
| Moon | 7.35e22 | 2.38 km/s |
| Mars | 6.42e23 | 5.03 km/s |
| Earth | 5.972e24 | 11.19 km/s |
| Jupiter | 1.898e27 | 59.5 km/s |
Approximate surface values for guidance. Enter the exact mass and radius above for a precise figure for any body.
Escape velocity calculator: frequently asked questions
What is escape velocity?
Escape velocity is the minimum speed an unpowered object needs at a body's surface to break free of its gravity and never fall back, ignoring air resistance and any further thrust. Above this speed the object's kinetic energy exceeds the gravitational potential energy binding it, so it can coast away to infinity.
Does escape velocity depend on the object's mass?
No. The formula v equals the square root of 2GM divided by r contains only the central body's mass M and radius r, not the mass of the escaping object. A pebble and a spacecraft need the same escape speed from the same point. Heavier vehicles simply need more energy to reach that speed.
What value of G does the calculator use?
It uses the gravitational constant G equal to 6.674 times 10 to the power minus 11 newton meters squared per kilogram squared, the value published by NIST. This constant is fixed in the calculation, so you only enter the central mass and the radius.
Why is Earth's escape velocity about 11.2 km/s?
Using Earth's mass of about 5.972 times 10 to the 24 kilograms and a surface radius of about 6.371 million meters, the formula gives roughly 11,186 meters per second, or about 11.19 kilometers per second. That is the speed needed to leave the surface and escape Earth's gravity entirely.
Does escape velocity account for atmosphere or orbit?
No. The formula gives the ideal escape speed in a vacuum from a point at radius r, ignoring atmospheric drag, planetary rotation and the gravity of other bodies. Real launches need extra energy to overcome drag, and reaching a stable orbit needs less speed than full escape.
Official sources
- Physical constants and gravitation references: US National Institute of Standards and Technology (NIST). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.