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. Each ephemeris swiss query is fed by NASA JPL DE431 data and returns ±0.001 arcsecond precision over 30 000 years of coverage. The same Swiss Ephemeris library powers Solar Fire, Janus, Kepler and Astrolog, the desktop tools the modern western tradition curated by Robert Hand, Chris Brennan and Demetra George cite as the reference for evidence-based astrology. The Project Hindsight school treats this kind of reproducibility as non-negotiable for a sceptical western audience.
NASA JPL Database
Based on DE431 ephemerides from NASA Jet Propulsion Labtimetory.
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.