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    Distance & light

    Astronomical Unit (AU) Converter

    Convert astronomical units to km, light-minutes, light-years and parsecs.

    1 AU = 149,597,870,700 m (exact, IAU 2012)

    Inputs

    Results

    Kilometres
    149,598,000 km
    Astronomical units
    1 AU
    Light-years
    1.58125 × 10^-5 light-years
    Parsecs
    4.84814 × 10^-6 parsecs
    Light travel time
    8 min 19.0 s
    Worked solution
    1. 1.496 × 10^11 m ÷ 1.496 × 10^11 = 1 AU
    2. 1.496 × 10^11 m ÷ 9.4607 × 10^15 = 1.5813 × 10^-5 ly
    3. 1.496 × 10^11 m ÷ 3.0857 × 10^16 = 4.8481 × 10^-6 pc

    How it works

    The astronomical unit was redefined in 2012 as an exact length, approximately the mean Earth–Sun distance.

    Variables

    • AU — astronomical unit = 149,597,870,700 m
    • ly — light-year = 9,460,730,472,580,800 m
    • pc — parsec ≈ 3.0857 × 10¹⁶ m

    Assumptions and limits

    • IAU 2012 exact AU; light-year uses the Julian year (365.25 days)
    • Parsec defined as 648,000/π AU (IAU 2015 Resolution B2)

    For education only. These models are simplified and are not suitable for spacecraft navigation or safety-critical engineering. See our scientific accuracy policy.