Escape Velocity Calculator
By Santaji GadepatilinUpdated October 27, 2026
Escape velocity is the speed an object needs to break free of a planet's gravity without any further push. It depends only on the planet's mass and radius — about 11.2 km/s for Earth.
How to use the escape velocity calculator
Enter the mass of the planet or moon and its radius. The calculator gives the escape velocity and the surface gravity. Defaults are for the Earth. Choose km/s by switching to m/s and dividing by 1,000, or read km/h directly.
Escape velocity formula
vesc = √(2GM ÷ R)
It comes from setting kinetic energy equal to the gravitational energy needed to reach infinity: ½mv² = GMm ÷ R.
Escape velocities in the solar system
| Body | Mass (kg) | Radius (km) | Escape velocity |
|---|---|---|---|
| Moon | 7.34e+22 | 1,737 | 2.38 km/s |
| Mercury | 3.3e+23 | 2,440 | 4.25 km/s |
| Mars | 6.42e+23 | 3,390 | 5.03 km/s |
| Venus | 4.87e+24 | 6,052 | 10.36 km/s |
| Earth | 5.97e+24 | 6,371 | 11.19 km/s |
| Neptune | 1.02e+26 | 24,622 | 23.56 km/s |
| Saturn | 5.68e+26 | 58,232 | 36.09 km/s |
| Jupiter | 1.9e+27 | 69,911 | 60.20 km/s |
| Sun | 1.99e+30 | 696,340 | 617.48 km/s |
Escape vs orbital velocity
Escape velocity is √2 (about 1.414) times the circular orbital velocity at the same distance. Low Earth orbit needs about 7.8 km/s; escaping from that altitude needs about 11 km/s. See the orbital period calculator.
Why the Moon has no atmosphere
Gas molecules move at hundreds of metres per second. On the Moon, with an escape velocity of only 2.4 km/s, the fastest molecules eventually escape, so it cannot hold a thick atmosphere.
Frequently asked questions
What is the escape velocity of Earth?
About 11.2 km/s (40,300 km/h) from the surface, ignoring air resistance.
Does escape velocity depend on the mass of the rocket?
No. It depends only on the mass and radius of the planet. A heavier rocket needs more energy, but the same speed.
Do rockets really travel at escape velocity?
Not necessarily — rockets keep firing their engines, so they can escape at lower speeds. Escape velocity is the speed needed for an unpowered object launched once.
What has an escape velocity faster than light?
A black hole, inside its event horizon.