Escape Velocity Calculator
Calculate escape velocity for Earth, other planets or any custom mass and radius with this free physics calculator that runs in your browser.
100% FreeRuns in your browserIntermediate
Enter Values
Minimum 0
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.
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- Light Travel Time Calculator
- Light-Year Converter
Explore more in Astronomy & Navigation.
Cite this tool
Zerdly. (2026). Escape Velocity Calculator. Retrieved from https://www.zerdly.com/tools/escape-velocity-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.