Light year au to parsec converter

Reviewed by the CalculatorHub team, edited by James Graham. Method from NIST SP 811 / BIPM SI. Last verified 2026-06-22.

The Light year au to parsec converter computes light year au to parsec from the relation pc = ly x 0.30660139378555057. It takes a single input (light year au in ly) and returns the parsec in pc. These converters are for anyone who has a quantity written in one unit and needs it in another before acting on it: shoppers and cooks working from foreign packaging or recipes, students and technicians reading specifications drafted in a different system, and travellers and tradespeople judging whether a figure quoted in units they do not work in every day fits the limit they have to meet. Enter your values below and the result updates instantly, and you can share a permalink that pre-fills the exact calculation. Check that the unit named on the figure in front of you is the one you have selected, since names such as gallon, ton and ounce each cover more than one definition; convert directly from the original number rather than stepping through intermediate units; and carry no more decimal places into the answer than the original measurement genuinely had, because a converted value cannot be more precise than the reading behind it. For example, with light year au = 10 ly, the parsec works out to 3.066014 pc, and the worked example further down the page shows every step so you can follow the arithmetic and reproduce it by hand. The method is the standard form documented by NIST SP 811 / BIPM SI, and the figure above each result carries the date it was last verified. Some unit pairs convert by an exact rule while others give a result that never terminates and has to be rounded to fit the display, so the last digit shown here can differ from what another converter displays, and where a converted quantity governs a trade, dosing or contractual amount it is the tolerance allowed for that transaction, not the decimals on screen, that decides whether the value passes.