🔭 Astronomy Calculator

Escape Velocity
Calculator

Calculate the minimum speed required to escape the gravitational pull of any planet, moon, or star. Select a preset or enter custom values.

📐 Formula
v = √(2GM / r)
v = Escape velocity in metres per second (m/s)
G = Gravitational constant — 6.674 × 10⁻¹¹ N·m²/kg²
M = Mass of the planet or body in kilograms (kg)
r = Radius of the body in metres (m)
🚀 Escape Velocity Calculator

What is Escape Velocity?

Escape velocity is the minimum speed an object must reach to break free from a planet's gravitational pull without any further propulsion. Once an object reaches this speed, gravity can no longer pull it back — it will continue moving outward forever (ignoring other forces).

Why it depends on mass AND radius

A planet twice as massive will have a higher escape velocity. But a planet with the same mass compressed into a smaller radius will also have a higher escape velocity — because you start closer to the centre of gravity. This is why black holes have escape velocities exceeding the speed of light.

🌍 Earth's escape velocity is 11.186 km/s (about 40,270 km/h). Every rocket leaving Earth must reach this speed to avoid falling back. In practice, rockets don't go straight up — they use orbital trajectories which require less fuel.

Escape velocities in our solar system

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