Work out parsec conversion instantly with clear inputs, formula shown and shareable results.
Parallax distance is simply the reciprocal of the annual parallax in arcseconds: d = 1/p parsecs. Proxima Centauri's 0.7687 arcsecond parallax gives 1.301 parsecs, or 4.24 light years. Gaia measures parallaxes to microarcseconds, extending reliable geometric distances to tens of thousands of parsecs.
Parallax distance
d(parsecs) = 1 / parallax(arcseconds)
Unit relation
1 parsec = 3.26156 light years
Because parallax angle shrinks with distance. A star twice as far shifts half as much against the background over a year.
Angular precision. Ground-based work reached about 0.01 arcseconds; Hipparcos reached 0.001 and Gaia around 0.00002.