One parsec is _____ light years.

Parsec in Light-Years:

1. Parsec is defined as the distance to an object with a parallax angle of $1$ arcsecond.
2. Parsec is a mathematical unit of length.
3. A light-year is a distance covered by light in a duration of one year.
4. One parsec $=3.08\times {10}^{16}m$.
5. One light-year $=9.46\times {10}^{15}m$.
6. So one parsec $=\frac{3.08\times {10}^{16}}{9.46\times {10}^{15}}=3.26$ light-years.

Hence, one parsec is $3.26$ light years.