Calculation accuracy
Sidereal chart accuracy.
5,000 birth charts compared with Swiss Ephemeris for each ayanamsa, across seven house systems.
Evidence: Sidereal charts
| Sidereal setting | Sun–Pluto positions | House cusps | Asc / MC |
|---|---|---|---|
| Lahiri | <0.011″ | <0.010″ | <0.008″ |
| Fagan–Bradley | <0.019″ | <0.018″ | <0.018″ |
| Krishnamurti (KP) | <0.079″ | <0.079″ | <0.077″ |
Sidereal house calculation
Continuous systems use Swiss Ephemeris's apparent tropical cusps, then subtract the selected ayanamsa. Whole Sign houses begin at the zodiac sign containing the Ascendant. This is not a comparison with Swiss Ephemeris's separate native sidereal-house mode.
About the comparison
The charts cover dates from 1900–2100 and locations between 50° south and 50° north. Comparisons use apparent geocentric positions from the Sun through Pluto, with Swiss Ephemeris 2.08 as the reference.
House systems compared: Placidus, Whole Sign, Equal, Koch, Porphyry, Regiomontanus and Campanus.