The linear speed of Earth in its orbit around the Sun is approximately 107,300 kilometers per hour, or about 67,062 miles per hour. That speed is equivalent to 29.78 kilometers per second or 18.5 miles per second.
The linear speed, or velocity, at which Earth travels around the Sun can be calculated by assuming that Earth travels in a circle around the sun at a radius of 149.59 million kilometers. The velocity can then be found by using the formula for the circumference of a circle, which is 2 x pi x radius. This gives the velocity in years, which can then be converted into hours or seconds.