What is Shadbala in astrology?
Shad means six and bala means strength: Shadbala is the six-fold strength of a graha, six separately computed quantities added into one figure. It exists because "exalted" and "debilitated" are too blunt to settle real questions. A graha can be exalted and still weak, hemmed by malefic aspects, born at the wrong time of day, moving at a crawl, and Shadbala is the classical attempt to put a number on all of that at once. Everything is expressed in virupas, and sixty virupas make one rupa. The figure is computed for the seven grahas from the Sun to Saturn; Rahu and Ketu have no Shadbala in this scheme, since several of the six components have no meaning for a shadow point.
What are the six balas in Shadbala?
Six quantities, computed separately and then added into one figure. Three of them read where the graha stands: Sthana bala from its sign and house, Dig bala from its distance to a cardinal point of the chart, and Drik bala from the aspects falling on it. Two read the moment of birth rather than the chart: Kaala bala and Cheshta bala. The sixth, Naisargika bala, reads nothing at all and is identical in every chart ever cast. They are not built alike either: Sthana bala is a sum of five components and Kaala bala of nine, while Naisargika bala is a single fixed number per graha.
Sthana bala: strength of position
Positional strength (what the sign and the house are worth), and itself a sum of five components. Uchcha bala measures distance from the point of deep debilitation: a full 60 virupas at exact exaltation, nothing at exact debilitation. Saptavargaja bala reads dignity across seven divisional charts. Oja-yugma bala rewards odd or even sign placement in the Rasi and the Navamsa. Kendra bala pays 60 virupas in an angle, 30 in a succedent house and 15 in a cadent one. Drekkana bala adds 15 for ruling the decan the graha occupies.
Kaala bala: strength of the moment
Temporal strength, and the widest of the six: nine components, every one read off the birth moment rather than off the chart. Day or night birth (the Sun, Jupiter and Venus are counted strong by day, the Moon, Mars and Saturn by night), then the lunar phase, the third of the day, and the lords of the year, month, weekday and hora, worth 15, 30, 45 and 60 virupas in turn. Last come the graha's declination and planetary war, the correction applied when two grahas from Mars to Saturn stand within a degree of one another.
Dig bala: strength of direction
Directional strength, and the one component measured in degrees rather than by sign. Each graha has a cardinal point of the chart where it is worth the full 60 virupas, and the figure falls away linearly to zero at the point opposite. Mercury and Jupiter are strongest at the ascendant, the Sun and Mars at the midheaven, Saturn at the descendant, and the Moon and Venus at the fourth cusp. Because it reads an exact angle, it is the component a rounded birth time damages most.
Cheshta bala: strength of motion
Motional strength, taken from the cheshta kendra: how far the graha stands from the point governing its apparent speed, which is what makes a graha appear to slow, halt and turn retrograde as seen from the Earth. A graha near that turning scores highly here, which is the classical reason retrogression is not read as a weakness on its own. We follow the convention that gives the Sun and Moon none of this bala, neither of them being capable of retrogression.
Naisargika bala: natural strength
Natural strength: a fixed ladder by brightness, the same in every chart ever cast. The Sun holds 60 virupas, the Moon 51.43, Venus 42.86, Jupiter 34.29, Mercury 25.71, Mars 17.14 and Saturn 8.57, and nothing in a chart can move any of them. It is why a ranking by raw total flatters the Sun and penalises Saturn before a single position has been read, and why the ratio of a total to that graha's own minimum is the fairer comparison.
Drik bala: strength from aspects
Aspectual strength, and the only one of the six that can come out negative. Every graha aspects every other along the classical drishti curve, which includes the special aspects: Mars on the 4th and 8th, Jupiter on the 5th and 9th, Saturn on the 3rd and 10th. The virupas received from natural benefics are added, those received from natural malefics subtracted, and the net is quartered. A graha well placed by sign but heavily aspected by malefics gives back here what it gained there.
What is a good Shadbala score, and what is the minimum required?
Each graha has its own bar, and comparing a raw total with anything else is meaningless until you divide by it. The classical minimums in rupas are Sun 5, Moon 6, Mars 5, Mercury 7, Jupiter 6.5, Venus 5.5 and Saturn 5 (in virupas: 300, 360, 300, 420, 390, 330 and 300). Divide a graha's total by its own requirement and you get the ratio this calculator bands: 1.0 or above meets the minimum, 1.5 and above is very strong, 0.75 to 1.0 is slightly short, and below that is short of the minimum. Mercury sets the highest bar at 7 rupas and is therefore the graha most often found wanting; the Sun, Mars and Saturn have the lowest at 5.
Does a high Shadbala mean the planet is good?
No, and this is the most common misreading of the whole system. Shadbala measures capacity, not benevolence. It says how much power a graha has to do whatever it is going to do; what it does is settled by its nature, the houses it rules and the houses it occupies. A strong Saturn is a Saturn that acts strongly, including in the slow, exacting way Saturn acts. A weak benefic is not a bad benefic, it is one read as constrained rather than denied. That is deliberately how the bands on the results page are worded: a graha under its minimum is labelled capacity constrained, never unlucky. Strength tells you how loudly a graha speaks, not what it says.
Which planet has the highest Shadbala in my chart?
The results page names the planet with the highest Shadbala two ways, and the two often disagree. Ranking by raw virupa total gives the loudest graha in the chart, and that is the headline. But the ranking is skewed before the chart is even cast, because Naisargika bala is fixed and unequal: the Sun starts with 60 virupas of natural strength and Saturn with 8.57, a gap of more than 51 virupas that no placement can undo. Ranking by ratio to the required minimum asks a different and often more useful question: which grahas in this chart clear their own bar. A chart can easily have the Sun highest by total and Saturn better placed against its own requirement, so both are shown.
What does Shadbala in rupas mean?
The rupa is the unit the classical texts state their thresholds in, and the virupa is a sixtieth of it, the same relationship as a degree to a minute of arc. Every component here is computed in virupas, because most of the classical rules are stated as whole virupas: 60 for a graha at its own direction, 15 for its own decan, 30 or 15 for odd and even sign placement. The total is then divided by 60 and printed as rupas so it can be read against the published minimums. A number given as "Jupiter 6.8" is rupas; the same figure in virupas is 408. Quoting one as the other is the commonest way to make a strong graha look weak by a factor of sixty.
How is Shadbala calculated here, and which conventions do we use?
Positions are sidereal (nirayana) with Lahiri (Chitrapaksha) ayanamsha, and angular placement uses whole-sign bhavas: a graha in the same sign as the ascendant is in a kendra, worth 60 virupas, whatever its degree. That is a choice, and it moves the number: a cusp-based system such as Bhava Chalit can put a graha late in the ascendant's sign into the next bhava instead, which costs it the whole 60. Dig bala is the opposite, measured in degrees from the exact angle rather than by sign, so two grahas in the same sign can be worth 60 virupas and almost nothing. On Cheshta bala we follow the convention that gives the Sun and Moon none; other texts instead credit the Sun its Ayana bala and the Moon its Paksha bala, which raises both totals without changing the other five grahas.
What is the difference between Shadbala and Ashtakavarga?
They grade different things and are not interchangeable. Shadbala grades the graha: how much power this planet holds in this chart. Ashtakavarga grades the sign: how supportive a stretch of the zodiac is to whatever crosses it. A strong graha transiting a bindu-poor sign and a weak graha transiting a rich one are both ordinary, which is why the two are read side by side rather than one instead of the other. Our Ashtakavarga calculator covers the second. The full kundli adds a third view, Bhava Bala, which applies the same idea to the twelve houses, where a house is considered strong from 7 rupas.
How this is calculated
Nirayana rashis with the Lahiri (Chitrapaksha) ayanamsha and whole-sign bhavas, computed to arc-second accuracy. Sunrise and sunset are the ones almanacs show, the Sun's upper edge with refraction, so the daily windows agree with the calendars you compare them with. More on our method.