Swiss Ephemeris Online Ascendant Calculator and Birth Chart Tool
The world gold standard for precision astronomical calculations, developed by Astrodienst.
What is Swiss Ephemeris?
Swiss Ephemeris is the high-precision astronomical library Dieter Koch and Alois Treindl maintain at Astrodienst in Zurich. Stars.expert exposes it directly as a free swiss ephemeris birth chart calculator and as the swiss ephemeris online ascendant calculator that runs in your browser — no signup, no credit card. The same library powers desktop software like Solar Fire, Janus, Kepler and Astrolog, which astrologers already cross-check against each other; running it here means the same numbers, without installing anything.
Extreme Precision
±0.001 arcseconds - the highest precision available.
Global Coverage
Valid calculations for any location on Earth with automatic timezone handling.
Verifiable
Our calculations can be verified with external sources like NASA Horizons.
Technical Specifications
| Time Coverage | 13.201 a.C. - 17.191 d.C. |
| Precision | ±0.001 arcseconds |
| Data Source | NASA JPL DE431 |
| Celestial Bodies | Sun, Moon, 8 Planets, Major Asteroids, Lunar Nodes |
Experience the Precision
Generate your birth chart with the highest accuracy available.