Escape Velocity by Planet Calculator
Find the escape velocity from Earth, the Moon, Mars and other bodies — or from any custom mass and radius.
How it works
v_escape = √(2·G·M / r) (G = 6.674×10⁻¹¹ N·m²/kg²)
Escape velocity is the speed at which an object’s kinetic energy exactly matches the gravitational energy binding it to a body, letting it coast away forever without further push. It rises with the body’s mass and falls as you start farther from its centre, and it does not depend on the mass of the escaping object. A projectile launched at this speed would escape; anything slower falls back.
Worked example
For Earth (M = 5.972×10²⁴ kg, r = 6.371×10⁶ m): v = √(2 × 6.674×10⁻¹¹ × 5.972×10²⁴ ÷ 6.371×10⁶) ≈ 11,186 m/s, or about 11.2 km/s.
Sources: Escape velocity — Wikipedia
Frequently asked questions
Does escape velocity depend on the rocket’s mass?
No. The escaping mass cancels out of the energy balance, so a pebble and a spacecraft need the same escape speed from the same starting point. What differs is the energy — and fuel — needed to reach it.
Why is the Moon’s escape velocity so much lower?
The Moon has far less mass than Earth, so its gravitational binding energy is smaller. Its escape velocity is about 2.4 km/s, roughly a fifth of Earth’s — which is why the lunar lander could leave with modest engines.
Do rockets actually reach escape velocity at launch?
Not instantly. They accelerate gradually and often park in orbit first, then boost onto an escape trajectory. The figure here is the ideal speed needed at the surface with no air drag or ongoing thrust.
Related calculators
Educational estimate. Check the formula and units for your exact case.