In the new astronomical convention, the equivalent of a single Astronomical Unit is 149,597,870.7 kilometers (or 92,955,807 miles). This is the mean distance between the Earth and the Sun, however, since the distance is subject to variation during the orbital cycle of the Planet. The distance between the Earth and the Sun, in other words, usually varies over a single year.
Over the course of a year, the Planet ranges from 147,095,000 km (91,401,000 mi) from the Sun at the perihelion (its nearest point) to 152,100,000 km (94,500,000 mi) at the aphelion (its furthest point) – or from a distance of 0,983 AUs to 1,016 AU.
Astronomical unit (AU), a unit of length essentially equal to the actual or total distance between Earth and the Sun, defined as 149,597,870.7 km. Alternatively, the length of the semi-major axis, that is, half the actual diameter , of Earth’s elliptical orbit around the Sun can be regarded.