Convert Parsec (pc) to Barleycorn (barleycorn) instantly.
About these units
Parsec (pc)
A parsec is equal to 3.26 light years, or approximately 3.0857 × 10¹⁶ meters. It is defined based on the method of stellar parallax, the apparent shift in a star's position caused by Earth's orbit around the Sun. Specifically, a star at a distance of one parsec exhibits a parallax angle of one arcsecond (1/3600 of a degree). Because its definition emerges directly from geometric measurement techniques, the parsec became the standard astronomical unit for professional research. Parallax-based distances are foundational to the cosmic distance ladder — the sequence of methods by which astronomers measure distances from nearby stars to the farthest galaxies. The parsec is widely used in astrophysics because calculations involving gravitational dynamics, luminosity, or galactic structure often become more intuitive in parsecs than in light years. Although less familiar to the public, it is the preferred unit in scientific publications, planetary catalogs, and distance mapping of the Milky Way.
Barleycorn (barleycorn)
The barleycorn is an English unit, approximately 1/3 inch (8.47 mm), originally based on the length of a grain of barley. It served as a small-scale measure in tailoring, shoe sizing, and other crafts. In particular, the English shoe size system was historically based on barleycorns, with increments in size corresponding to single barleycorn units. This unit exemplifies the anthropometric and agronomic origins of measurement. Even today, the barleycorn's influence persists in the traditional shoe sizing system in the UK and the US, providing continuity with historical practices.