Escape Velocity Calculator
Calculate the escape velocity and low-orbit speed of Earth, the Moon, Mars, Jupiter, the Sun or any body from its mass and radius.
How fast you must go to leave a planet for good.
How the escape velocity calculator works
Escape velocity is the speed at which kinetic energy equals the gravitational potential energy binding an object to a body: √(2GM ÷ r). It does not depend on the mass of the escaping object. Circular orbital speed just above the surface is √(GM ÷ r), a factor √2 lower.
Pick a body or enter a mass and radius in Detailed mode. Real rockets do not need to hit escape velocity instantly — they keep thrusting — but the energy required is the same.
Formula: v_esc = √(2GM ÷ r) · v_orbit = √(GM ÷ r)
Worked examples
| Inputs | Escape velocity | Note |
|---|---|---|
| Earth | 11.19 km/s | 11.19 km/s |
| Moon | 2.38 km/s | 2.38 km/s |
| Jupiter | 60.2 km/s | 60 km/s |
FAQFrequently asked questions
Why does escape velocity not depend on the object's mass?
Both the kinetic energy and the gravitational binding energy are proportional to the object's mass, so it cancels. A feather and a rocket need the same speed.
Do rockets really reach 11 km/s?
To leave Earth's gravity entirely, yes — but gradually, thrusting for minutes. Low Earth orbit needs about 7.8 km/s.
What about air resistance?
The formula ignores it. Real launches climb through the atmosphere slowly first, then accelerate where the air is thin.
What is a black hole in these terms?
A body whose escape velocity at its surface exceeds the speed of light — the Schwarzschild radius r = 2GM ÷ c².
Where these figures come from
- NIST — CODATA 2018 fundamental physical constants — G, g₀, R, c
- NIST Special Publication 811 — Guide for the use of the International System of Units — unit conversions
- The Engineering ToolBox — material properties — specific heats, expansion coefficients, densities
- National Measurement Institute — Australia's measurement authority
Last checked: September 2026. Constants are the CODATA 2018 values; formulas are the standard textbook forms.