Escape Velocity Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserIntermediate
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the surface gravity and the body's radius.
- Read the escape velocity.
How it works
Escape velocity = √(2 × surface gravity × radius).
Worked example
Earth (9.81 m/s², 6371 km). ≈ 11.2 km/s.
Common mistakes
- Entering radius in metres — use kilometres here.
- Confusing escape velocity with orbital velocity (orbit needs less).
Frequently asked questions
What's Earth's escape velocity?
About 11.2 km/s — the speed needed to break free of Earth's gravity without further propulsion.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.