Escape Velocity Calculator
Speed needed to leave a gravity well.
Enter your values
Enter the mass in kg.
Enter the radius in m.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Escape velocity
- 11185.98 m/s
- In km/s
- 11.186
- In mph
- 25,022
- Surface gravity
- 9.82 m/s²
- Orbital velocity (low orbit)
- 7.9097 km/s
Quick answer
Escape velocity is √(2GM/r) — the speed at which kinetic energy exactly cancels gravitational binding energy.
v = √(2GM/r)
At a glance
| What it does | Speed needed to leave a gravity well. |
|---|---|
| Category | Science |
| Inputs needed | Mass, Radius |
| Main output | Escape velocity |
| Formula | v = √(2GM/r) |
| Cost | Free — no sign-up, no download |
How to use the Escape Velocity Calculator
- 1Enter the body's mass in kilograms.
- 2Enter its radius in metres.
- 3Scientific notation like 5.972e24 is accepted.
Inputs explained
- Mass(kg)
- Enter the mass in kg.
- Radius(m)
- Enter the radius in m.
Worked example
Using the values the calculator loads with:
Inputs
- Mass5.972e24 kg
- Radius6371000 m
Results
- Escape velocity11185.98 m/s
- In km/s11.186
- In mph25,022
- Surface gravity9.82 m/s²
- Orbital velocity (low orbit)7.9097 km/s
Frequently asked questions
What is Earth's escape velocity?
About 11.2 km/s, or 25,000 mph.
Does it depend on the escaping object's mass?
No — it is the same for a pebble or a rocket.
What do I need to enter into the Escape Velocity Calculator?
Just 2 values: mass, radius. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Escape Velocity Calculator work out the answer?
Escape velocity is √(2GM/r) — the speed at which kinetic energy exactly cancels gravitational binding energy. It applies the formula v = √(2GM/r) and shows the working so you can check each step by hand.
Is the Escape Velocity Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.