House Systems
Division Logic Comparison
Calculate how house cusps translate mathematically across varied frameworks.
The Math of Houses: Dividing the 3D Sky
How do we divide the sky into 12 "Houses" (Bhavas)? This is the ultimate challenge of projection geometry.
Equal HouseSimply divides the Ecliptic into 12 equal slices from the Ascendant.
Sripathi / PorphyryDivides the arcs between the 4 angles (Asc, MC, Des, IC) into 3 parts.
PlacidusA time-based system that divides the semi-diurnal arc of each degree.
The Takeaway: Different house systems are just different mathematical "cameras" looking at the same 3D sky. There is no "true" system, only different ways of measuring the same reality.
Cusp Distribution Wheel
Angles (Cusps 1, 4, 7, 10)
Intermediate Cusps
| House | Cusp Angle | Size |
|---|---|---|
| House 1 | 0.0° | 30.0° |
| House 2 | 30.0° | 30.0° |
| House 3 | 60.0° | 30.0° |
| House 4 | 90.0° | 30.0° |
| House 5 | 120.0° | 30.0° |
| House 6 | 150.0° | 30.0° |
| House 7 | 180.0° | 30.0° |
| House 8 | 210.0° | 30.0° |
| House 9 | 240.0° | 30.0° |
| House 10 | 270.0° | 30.0° |
| House 11 | 300.0° | 30.0° |
| House 12 | 330.0° | 30.0° |
Select Framework
Cusps spaced identically by exactly 30 degrees. The Ascendant determines the start of the 1st house, and all subsequent houses are exactly 30° wide.
Based on sacred traditions. May divine grace be with you.