Convert Julian Years to Gregorian Years
Convert Julian Years (a_J) to Gregorian Years (yr) instantly and accurately.
Conversion Formula
yr = a_J × 1.000020534
About Julian Years
The Julian year (a_J) = exactly 365.25 days = 31,557,600 s - the IAU standard year for astronomical distances. The light-year is formally 1 ly = c × 1 a_J = 9.461 × 10¹⁵ m (IAU 2012 B2). Julian years differ from Gregorian years by only 648 s (~10.8 min/year); important for high-precision astrometry or calculations spanning centuries. 1 a_J = 365.25 d = 31,557,600 s.
About Gregorian Years
The Gregorian year = exactly 365.2425 days = 31,556,952 s (mean over the 400-year cycle with 97 leap years). The Julian calendar (45 BCE) used 365.25 days; Gregorian reform (1582) dropped 10 days and amended the centennial rule. Britain adopted it in 1752; Greece in 1923. Carbon-14 dates are reported in 'years BP' (before 1950 CE). 1 yr = 365.2425 d = 8,765.82 h = 31,556,952 s.
Quick Reference Table
| Julian Years (a_J) | Gregorian Years (yr) |
|---|---|
| 1 a_J | 1.00002 yr |
| 2 a_J | 2.00004 yr |
| 5 a_J | 5.0001 yr |
| 10 a_J | 10.0002 yr |
| 25 a_J | 25.0005 yr |
| 50 a_J | 50.001 yr |
| 100 a_J | 100.002 yr |