Escape Velocity Calculator
How fast do you need to go to escape Earth's gravity? Escape velocity is the minimum speed needed for an object to break free from a body's gravitational pull without further propulsion. This calculator computes escape velocity from any spherical mass, from asteroids to stars. Just enter the mass and radius, or use presets for planets and moons.
How We Calculate This
Escape velocity v = √(2GM/R), where G = 6.67430 × 10⁻¹¹ m³/(kg·s²), M is the body's mass, and R is its radius. Kinetic energy per unit mass = ½v² = GM/R.
Frequently Asked Questions
What is escape velocity?
Escape velocity is the minimum speed an object needs to escape a body's gravitational field without any further propulsion. At this speed, the object's kinetic energy equals the gravitational potential energy needed to reach infinity.
Why is escape velocity independent of the escaping object's mass?
The formula v = √(2GM/R) doesn't include the escaping object's mass because both kinetic energy (½mv²) and gravitational potential energy (GMm/R) are proportional to it. The mass cancels out.
Do rockets need to reach escape velocity?
Not necessarily! Rockets can escape at any speed if they continue thrusting. Escape velocity only applies to unpowered projectiles. Rockets typically use much slower continuous burns to reach orbit.
What if escape velocity exceeds light speed?
If escape velocity exceeds the speed of light, you have a black hole! The Schwarzschild radius is where escape velocity equals c. Nothing, not even light, can escape from inside this radius.
Why is Jupiter's escape velocity so high?
Escape velocity depends on both mass and radius: v = √(2GM/R). Jupiter is massive but also large, so its escape velocity (59.5 km/s) is about 5× Earth's despite having 318× the mass.
Related Calculators
You might also find these calculators helpful: Weight on Other Worlds, and Asteroid Impact.