How many kilometres equal one astronomical unit?

Hint: Astronomical units (AU) are units of measure used to compute the distance between the Earth and the Sun. Astronomers measure the distance between celestial bodies of our solar system in terms of astronomical units.

Complete answer:
 One astronomical unit (AU) = 92,955,807 miles or 149,597,871 km or 93 million miles 150 million km, (8 light-minutes). AU is a convenient measuring unit to calculate the mean distance between the Earth and the Sun and provides ease in doing numerous astronomical calculations. The Earth's distance varies throughout the year as it doesn't have a perfect orbit around the Sun. Thus the astronomers give relative measurements in terms of Astronomical units(AU).

Astronomical units(AU) and light years are both used as measuring units of space. Light years are too big approximations as it is equal to almost 6 trillion miles. Thus sometimes, for an astronomer, light years do not serve the purpose. Thus they heavily rely on Astronomical units(AU). Parsec is another measuring unit that is used to calculate large distances between celestial bodies outside the solar system. One parse is equal to 31 trillion kilometres or 19 trillion miles.

Note:Astronomical units (AU) are one of the units of measure used by astronomers for the relative distance between heavenly bodies, particularly the average distance between the Earth and the Sun. The Earth's orbit around the Sun is elliptical. As a result, the distance between them keeps changing. Astronomers find Astronomical units(AU) better than light years to capture the volatility of the planetary objects.