What is the escape velocity formula?

v = sqrt(2GM/R), where G = 6.674 × 10⁻¹¹ N·m²/kg² is the gravitational constant, M is the body's mass in kg, and R is its radius in meters. The result is in m/s.

Does the mass of the escaping object matter?

No. The escaping object's mass cancels out in the derivation, so escape velocity depends only on the planet's mass and radius.

What is Earth's escape velocity?

Earth's escape velocity is approximately 11.19 km/s (about 40,270 km/h or 25,020 mph) from its surface.

Is escape velocity the same as orbital velocity?

No. Orbital velocity (for a low circular orbit) is v_orb = sqrt(GM/R), which is exactly 1/sqrt(2) ≈ 0.707 times the escape velocity. Escape velocity is sqrt(2) times higher.

What happens if a spacecraft travels at exactly escape velocity?

It will just barely escape to infinity, arriving with zero residual velocity. In practice, rockets aim for somewhat higher speeds to reach interplanetary trajectories efficiently.

Why does the Moon have no atmosphere?

The Moon's escape velocity is only about 2.38 km/s. Gas molecules at typical temperatures can reach speeds close to or above this, so they gradually escape into space over geologic time.

Escape Velocity From Planet

Enter a planet mass and radius (or pick a preset) to calculate the minimum speed needed to escape its gravity.

Planet Parameters

Quick Presets

Planet Mass (kg)

Scientific notation accepted (e.g. 5.972e24)

Mean Radius (km)

Results

Enter values and click Calculate

Copied!

Summary

Enter a planet mass and radius (or pick a preset) to calculate the minimum speed needed to escape its gravity.

How it works

Select a Solar System preset to auto-fill mass and radius, or enter custom values.
Confirm or adjust the planetary mass (kg) and mean radius (km).
Click Calculate to apply v = sqrt(2GM/R).
The result is shown in km/s, m/s, and mph for convenience.
Use the copy button next to any result to copy it to your clipboard.

Use cases

Determine how fast a rocket must travel to leave Earth's gravity without extra thrust.
Compare escape velocities across Solar System bodies for astrophysics coursework.
Understand why the Moon has negligible atmosphere (low escape velocity).
Explore hypothetical bodies by entering custom mass and radius values.
Verify textbook escape velocity figures for any planet or moon.
Support science-fiction world-building with physically accurate planet data.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu