Shadbala

Ṣaḍbala— "six-fold strength" — is the classical method for quantifying a planet's capacity to deliver the results promised by its position. Every planet has both potential (what the chart promises through dignity, house, yogas) and capacity (whether the planet can act on that potential at all). Shadbala measures capacity.

The six components of Shadbala measure orthogonal sources of strength. They sum to a total measured in rūpas(units; 60 ṣaṣṭyāṃśas = 1 rūpa), and that total is compared against each planet's classical requirement. A planet meeting or exceeding its requirement is called balvān (strong) — its promised results manifest. A planet below requirement is nirbala(weak) — results arrive partial, late, or not at all.

The six strengths

1. Sthāna Bala — positional strength

The densest component. Composed of five sub-balas:

Ucca Bala — exaltation strength

Maximum when the planet is at its exact exaltation degree; scales linearly to zero at its debilitation degree. Classical formula: based on the planet's angular distance from its deepest debilitation, reaching 1 rūpa at exaltation.

Saptavarga Bala — seven-varga dignity

Evaluates the planet's dignity across seven divisional charts (D1, D2, D3, D7, D9, D12, D30) with classical weights. A planet exalted in the D1 but debilitated across most of saptavarga scores poorly here — the principle that a planet's strength is its average behaviour, not its behaviour in one frame.

Ojayugma Bala — odd/even sign

Natural benefics (Moon, Mercury, Jupiter, Venus) prefer even signs; natural malefics (Sun, Mars, Saturn) prefer odd. Planets in their preferred gender score more here.

Kendrādi Bala — angularity

Full strength in a kendra (1, 4, 7, 10); half in a paṇaphara (2, 5, 8, 11); quarter in an āpoklima (3, 6, 9, 12). Classical weight on angular placement.

Drekkāṇa Bala — decanate strength

Uses the three 10° divisions of a sign. Masculine planets gain strength in the first decanate; feminine planets in the middle; neutral planets in the last.

2. Dig Bala — directional strength

Each planet has a direction where it performs best:

Dig bala is maximum in the peak house and decreases symmetrically to zero in the opposite house. A Jupiter in the 1st has full dig bala; a Jupiter in the 7th has zero.

3. Kāla Bala — temporal strength

The most computationally dense component, with eight sub-components:

• Nathonnata Bala — based on time from midnight/noon. Favours certain planets at night (Moon, Mars, Saturn) and others by day (Sun, Jupiter, Venus).
• Pakṣa Bala — lunar phase. Benefics gain in bright fortnight; malefics in dark. The Moon's pakṣa bala is particularly important.
• Tribhāga Bala — divides day and night into thirds, each ruled by a specific planet; the ruling planet receives strength.
• Abda, Māsa, Vāra, Horā Bala — the rulers of the year, month, day, and hour of birth each receive a fixed bonus.
• Ayana Bala — declination from the equator. The Sun's ayana bala is its primary motional signature.
• Yuddha Bala — planetary war. When two non-luminary planets are within 1° of each other, they fight; the one at the lower ecliptic latitude or higher altitude wins and gains strength, the other loses.

4. Cheṣṭā Bala — motional strength

Strength derived from speed and direction. Retrograde planets — and planets near their stations — gain cheṣṭā bala. The Sun uses a different rule: its cheṣṭā bala equals its ayana bala (since the Sun never retrogrades).

A retrograde Jupiter has more cheṣṭā bala than a direct one, which is why classical texts often interpret a retrograde benefic as "more capable" even while being less conventional in its expression.

5. Naisargika Bala — innate strength

A fixed intrinsic ranking, independent of the chart:

This reflects the classical ordering by apparent brightness. It serves as a tiebreaker: when two planets have otherwise similar shadbala, the higher-naisargika planet wins.

6. Dṛk Bala — aspectual strength

The net effect of all aspects cast onto a planet. Each aspect is computed as a signed value: benefic aspects add, malefic aspects subtract. Aspects follow the classical intensity curve — a 7th aspect (180°) is at full strength; sideways aspects diminish with distance. Special aspects from Mars, Jupiter, Saturn are weighted separately.

Total rūpas and required rūpas

Summing the six components gives the planet's total strength in rūpas. Classical tables specify how many rūpas each planet requires to be called strong:

The ratio of total to required rūpas is the cleanest single-number strength index. A ratio above 1.0 means the planet exceeds its classical requirement and delivers reliably. A ratio below 0.8 means the planet cannot deliver even simple promises in its dasha without external support.

Bhāva Bala — house strength

Separately from planetary shadbala, each of the twelve houses has its own strength composed of:

• Bhāvādhipati Bala — strength inherited from the house lord's shadbala.
• Bhāva Dig Bala — strength from occupying a directionally favourable sign.
• Bhāva Dṛk Bala — net aspects received by the house.

A house with high bhāva bala delivers its significations reliably regardless of its tenants. A house with low bhāva bala struggles even with benefics inside — the bhāva itself is weak at the structural level.