Convert Gregorian Years to Gigayears
Convert Gregorian Years (yr) to Gigayears (Ga) instantly and accurately.
Conversion Formula
Ga = yr × 1.000000000e-9
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.
About Gigayears
A gigayear (1 Ga) = 10⁹ yr ≈ 3.156 × 10¹⁶ s - the timescale of stellar evolution and cosmology. Universe age: 13.787 ± 0.020 Ga (Planck CMB). Sun: 4.603 Ga old; red giant in ~5 Ga. A 0.1 M☉ red dwarf lives ~10,000 Ga. Uranium-238 half-life = 4.468 Ga (used in radiometric dating). Proton decay (GUT prediction): ~10³⁴ yr = ~10²⁵ Ga. 1 Ga = 10⁹ yr.
Quick Reference Table
| Gregorian Years (yr) | Gigayears (Ga) |
|---|---|
| 1 yr | 1 × 10-9 Ga |
| 2 yr | 2 × 10-9 Ga |
| 5 yr | 5 × 10-9 Ga |
| 10 yr | 1 × 10-8 Ga |
| 25 yr | 2.5 × 10-8 Ga |
| 50 yr | 5 × 10-8 Ga |
| 100 yr | 1 × 10-7 Ga |