Escape Velocity Calculator
Speed needed to escape a body's gravity, and the speed needed to orbit it at the surface.
Results
Escape velocity
11,185.98
m/s
Speed
11.1860
km/s
Orbital velocity
7.9097
km/s
Acceleration
9.8200
m/s²
What this tool does
Escape velocity is exactly the square root of two times the circular orbital speed — about 11.2 km/s for Earth against 7.9 km/s to orbit. It assumes no atmosphere and no further thrust: a rocket that keeps burning never has to reach it in one go.
Formula
v = √(2 G M ÷ r)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
mp | Mass of the body | kg |
r | Radius | km |
V | Escape velocity | m/s |
VK | Speed | km/s |
VO | Orbital velocity | km/s |
GS | Acceleration | m/s² |
Worked example
- Mass of the body5.972e+24 kg
- Radius6371 km
- Escape velocity11,185.98 m/s
- Speed11.1860 km/s
- Orbital velocity7.9097 km/s
- Acceleration9.8200 m/s²
Limitations
- The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.