What is the escape velocity of Earth in kilometers per second?

The escape velocity of Earth is 11.186 km/s.

Escape velocity is the minimum speed an object needs, if no further propulsion is supplied, to move away from Earth indefinitely without falling back. The figure assumes an idealized Earth and ignores atmospheric drag, Earth’s rotation, and the gravitational influence of other bodies. It is calculated using the escape-speed equation, which depends on Earth’s mass and the distance from its center.

The value is often rounded to 11.2 km/s, or about 40,270 km/h. It is not the same as Earth’s surface gravitational acceleration, which is 9.80665 m/s². Acceleration describes how quickly velocity changes, while escape velocity is a speed.

A rocket does not need to leave the launchpad already traveling at 11.186 km/s. Real spacecraft build up speed through powered flight, and launching eastward can take advantage of Earth’s rotation. Atmospheric drag and the rocket’s need to carry fuel make actual missions more complicated than the ideal calculation.