Professional-Grade Vedic Calculations: BPHS Shadbala & Ashtakavarga

AstroSutra is the only Vedic astrology app we know of that ships a full BPHS-compliant Shadbala implementation with Panchadha Maitri friendship/enmity weighting and Drik Bala aspect strength. Most apps stop at sign placement, basic Dasha, and a few yogas. AstroSutra computes the full classical stack used by professional Jyotishis:

• Shadbala — six sources of planetary strength (Sthana, Dig, Kala, Cheshta, Naisargika, Drik), each broken down by classical sub-formula. Guarded by 4,290+ unit tests against reference Jyotish software.
• Ashtakavarga — Sarva Ashtakavarga and per-planet Bhinna Ashtakavarga, used for transit interpretation and Gochara Vedha analysis.
• Divisional charts (Shodashavarga D1–D60) — Navamsa (D9), Dasamsa (D10), Saptamsa (D7), Trimshamsa (D30), and the full 16-chart set, with deterministic Vargottama detection.
• Dual house system — Whole-Sign (Parashari) and Bhava Chalit (equal-house centered on the Lagna degree) computed in parallel, so yogas and aspects can be cross-checked against both.
• KP sub-lord hierarchy — Krishnamurti Paddhati sub-lord chain for event timing, including all 5 ruling planets at the moment of judgement.

The astronomy comes from Swiss Ephemeris, derived from NASA JPL ephemerides. The Vedic computation layer is in Python, deterministic, and version-pinned — the same birth data always yields the same numbers. Same engine across every tier; paid plans unlock depth of interpretation, not different math.