Escape Velocity Calculator
Fill in the values and the answer updates as you type.
How the Escape Velocity Calculator works
v = √(2GM ÷ r) with G = 6.6743 × 10⁻¹¹ N·m²/kg². The defaults are for Earth (mass 5.972e24 kg, radius 6,371,000 m). Example: with Body mass 5.972e24 kg, and Radius 6,371,000 m, the result is Escape velocity (km/s) = 11.19; Escape velocity (km/h) = 40,270; Surface gravity (m/s²) = 9.82.
Inputs and results
The Escape Velocity Calculator takes 2 inputs and gives 3 results.
What you enter
- Body mass (kg) — starts at 5.972E+24.
- Radius (m) — starts at 6371000.
What you get
- Escape velocity (km/s)
- Escape velocity (km/h)
- Surface gravity (m/s²)
Example: Escape Velocity Calculator with the starting values
With body mass 5.972E+24 kg and radius 6371000 m, the calculator returns:
| Escape velocity (km/s) | 11.19 |
|---|---|
| Escape velocity (km/h) | 40,270 |
| Surface gravity (m/s²) | 9.82 |
Change any value above and the results update straight away.
Escape Velocity Calculator FAQ
How do I use the Escape Velocity Calculator?
Enter body mass and radius in the fields, then read escape velocity (km/s), escape velocity (km/h) and surface gravity (m/s²) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Escape Velocity Calculator calculate?
Speed needed to escape a planet or moon. It returns escape velocity (km/s), escape velocity (km/h) and surface gravity (m/s²) from the 2 values you provide.
What values does the Escape Velocity Calculator start with?
It opens with body mass 5.972E+24 kg and radius 6371000 m so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Escape Velocity Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Escape Velocity Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.