Convert Gregorian Years to Shakes
Convert Gregorian Years (yr) to Shakes (sh) instantly and accurately.
Conversion Formula
sh = yr × 3.155695200e+15
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 Shakes
A shake = exactly 10 ns (10⁻⁸ s) - the informal unit for fission prompt-neutron generation time, coined at Los Alamos during the Manhattan Project (1943-1945). A prompt-neutron generation in a supercritical core takes ~1-10 shakes; a full explosive chain reaction unfolds over ~50-100 shakes. The name alludes to 'two shakes of a lamb's tail'. Still used in reactor physics and weapons-design calculations. 1 shake = 10 ns.
Quick Reference Table
| Gregorian Years (yr) | Shakes (sh) |
|---|---|
| 1 yr | 3.156 × 1015 sh |
| 2 yr | 6.311 × 1015 sh |
| 5 yr | 1.578 × 1016 sh |
| 10 yr | 3.156 × 1016 sh |
| 25 yr | 7.889 × 1016 sh |
| 50 yr | 1.578 × 1017 sh |
| 100 yr | 3.156 × 1017 sh |