The Earth's orbital velocity is not a single fixed number, but rather varies slightly depending on where it is in its elliptical orbit around the sun.

Here are some key points:

* Average orbital velocity: The Earth orbits the Sun at an average speed of 29.78 km/s (18.5 miles per second).

* Perihelion and Aphelion: The Earth's speed is slightly faster when it is closer to the sun (perihelion) and slower when it is farther away (aphelion).

* Orbital period: The Earth completes one orbit around the Sun in approximately 365.25 days, which is why we have a year.

To give you a sense of scale, the Earth travels over 940 million kilometers (584 million miles) in one year!