Compute the six classical sources of planetary strength - Sthana, Dig, Kala, Cheshta, Naisargika and Drik Bala - for all seven classical planets, from date, time and place of birth. Every value is in virupas and every row states the accuracy we measured for it. Uses the sidereal Lahiri ayanamsa and the same engine as our Kundli.
100% private - the whole calculation runs in your browser. No birth data sent anywhere.
This calculator computes all six classical sources of Shadbala - Sthana, Dig, Kala, Cheshta, Naisargika and Drik Bala - for all seven classical planets, in virupas, from your date, time and place of birth. Fourteen of its sixteen component rows reconcile to within a few hundredths of a virupa against the reference implementation we validate against, and the Sthana subtotal reproduces that reference on all seven planets. Saptavargaja alone draws on seven divisional-chart engines. Every row states its accuracy class, the charts that class was established on, and the largest deviation we measured - so you can check any number here rather than take it on trust. It runs entirely in your browser.
This tool shows the six sources of planetary strength separately. It does not produce a Shadbala total, a required-rupa ratio, or a strong/weak verdict.
A total is withheld because four components are not yet parity-grade against our reference implementation: Nathonnatha, exact Ayana, Graha Yuddha, and Cheshta. Our own rule is that a total stays null until every required component reaches parity, and we would rather ship six honest columns than one number carrying a known error we cannot bound.
Supports 1900 onwards for better calculation reliability.
Birth time feeds the Kala (time) components directly - the hora, the day/night thirds and the day lord all move with it.
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astrology| System | Shadbala (six-fold strength), BPHS Ch. 26-27 |
|---|---|
| Unit | Virupa (shashtiamsa); 60 virupas = 1 rupa |
| Bodies | The seven classical planets (Sun through Saturn); no Rahu/Ketu |
| Six sources | Sthana, Dig, Kala, Cheshta, Naisargika, Drik |
| Sthana parts | Uccha, Saptavargaja, Ojayugma, Kendradi, Drekkana (subtotal shown) |
| Kala parts | Paksha, Tribhaga, Vara, Hora, Masa, Abda, Ayana - plus Nathonnatha, which is WITHHELD. No subtotal. |
| Total | NOT computed - four components are not yet parity-grade |
| Verdict / ranking | None. No required-rupa ratio, no strong/weak label |
| Inputs | Date, time, and place of birth |
| Engine | Meeus: VSOP87 for the planets, ch. 47 lunar theory for the Moon, plus the Lahiri ayanamsa (same engine as Kundli) |
| Privacy | 100% client-side; no birth data leaves your browser |
Shadbala - literally “six strengths” - is the Brihat Parashara Hora Shastra’s answer to a question the birth chart alone does not settle: a planet sits in a sign and a house, but how much force does it actually carry? The text answers it by measuring six independent things and expressing each in virupas, where sixty virupas make one rupa.
The six are Sthana Bala, positional strength, which asks how dignified the placement is - including across seven divisional charts, not just the birth chart; Dig Bala, directional strength, which asks how far the planet is from the direction in which it is classically weakest; Kala Bala, temporal strength, the largest group, covering the lunar fortnight, day versus night, the thirds of day and night, the weekday, the planetary hour, the month and year lords, and the solar hemisphere; Cheshta Bala, motional strength; Naisargika Bala, a fixed natural ranking running from the Sun down to Saturn; and Drik Bala, the net effect of the aspects the other planets throw at it.
Only Drik can go negative, and it regularly does - malefic aspects subtract. That is why you will see negative numbers in the Drik row and nowhere else.
The classical method sums the six into a Shadbala total, divides by sixty to get rupas, and compares that against a required-strength table to call a planet strong or weak. Most Shadbala calculators do exactly that. This one stops one step earlier, and the reason is worth stating plainly rather than hiding in a footnote.
We validate every component against a reference implementation and record the maximum deviation we measure. Most land within a few hundredths of a virupa. Four do not: Nathonnatha carries a known, time-dependent deviation that reaches about 4 virupas at the times we have measured; Ayana is approximate to about 0.36 virupas across our held set; Graha Yuddha is screened for but its correction is not computed, and we hold no verbatim source for the orb, the victor rule, or the order the correction is applied in; and Cheshta follows a source-prescribed convention that reproduces our reference to about 0.2 virupas without being parity-grade.
We deliberately do not quote a single number for what a total would be wrong by. The deviations do not occur simultaneously, they do not share a sign, and the Yuddha term is unquantified, so adding the maxima together would produce a confident-looking figure that no measurement supports - the exact failure this page exists to avoid. What can be said plainly is that the largest of them, Nathonnatha, reaches four virupas at the times we have measured, which is far outside the hundredths-of-a-virupa tolerance every other row here is held to, and is more than enough to reorder two planets sitting close together - precisely what a ranked strength table gets used for. So the components ship, each with its accuracy stated, and the total waits. If you want to see the parity work this rests on, our calculation method and accuracy post covers how the astrology engine is validated.
Each row below is the accuracy class we hold for that component, the charts the class was established on, and the largest deviation measured against our reference’s displayed value. Two things to read carefully. A validation on one or two charts is not universal parity, which is why the coverage column exists. And several of the reference’s bars print to one decimal place, so these deltas bound the distance to a displayed value - its unrounded internal figure could sit about 0.05 virupas either side, and that uncertainty sits on top of ours, not inside it.
| Component | Class | Coverage | Max deviation measured |
|---|---|---|---|
| Uccha | verse-anchored + parity-grade | Fixture 1 | 0.003v |
| Ojayugma / Kendradi / Drekkana | verse-anchored | Fixture 1 | identical at 2dp (integer ladders) |
| Saptavargaja | parity-grade | Two charts (fixture 1 CnL + fixture 3) | 0.005v |
| Sthana subtotal | reconciled sum | One chart (the held CnL fixture) | 0.0051v |
| Dig | parity-grade | Fixture 1, 7/7 | 0.048751v (Sun), against 1dp labels |
| Naisargika | parity-grade | Fixture 1, 7/7 | 0.042857v = pure 1dp label rounding on (2x60)/7; exact by construction |
| Drik | parity-grade | Fixture 1, 7/7 | 0.037019v (Venus), against 1dp labels |
| Cheshta | convention-specific, NOT parity-grade | Two charts (fixtures 1 and 2), 10 cells | 0.181v (Mercury) |
| Paksha / Tribhaga / Vara / Hora / Masa / Abda | reconciled | Fixture 1 | identical at 2dp |
| Nathonnatha | KNOWN DEVIATION, TIME-DEPENDENT | Fixture 1 at 06:00 / 12:00 / 18:00 | 4.028v worst of the three |
| Ayana | KNOWN DEVIATION | Held set of 28 cells (fixture 1 at 06:00/12:00/18:00 + fixture 2) | 0.36v OBSERVED over the held set |
Note that the numbers above are measurements, not the thresholds our regression tests use. The two are easy to confuse: our Sthana guard, for instance, fails the build at 0.02 virupas, but the deviation actually measured is 0.0051. Quoting a guard as if it were a result would overstate the error by four times.
The classical verses fix the STRUCTURE of each component - what it measures, and which planets or placements it favours. They do not always fix the arithmetic. And in one case we go further than filling a silence: the transcription DOES give a Saptavargaja ladder, but its printed integer rungs cannot reproduce the reference implementation, so the values we ship were solved numerically instead. That is a disagreement with the text, not a gap in it. Where a verse is silent, or where our reading of it disagreed with the reference we validate against, we chose the option that reproduced the reference and recorded it. Those choices are listed here rather than presented as textual authority.
| Component | What the text settles | What we ship, and why |
|---|---|---|
| Dig | BPHS 27.7-8 names each planet's weakest direction but does not define where the cusp sits. | Cusps are measured as equal arcs from the ascendant's DEGREE. Chosen because it reproduces all seven reference values; the house-based alternative does not. |
| Saptavargaja | BPHS 27.2-4 names the seven divisional charts AND gives a dignity ladder - the text is not silent here, it states integer rungs. | We do not ship the transcribed integers: they cannot reproduce the reference implementation. The six lower rungs were solved numerically instead, and land on fractional values at display precision. This is the one row where we knowingly override a figure the text supplies, rather than filling a gap it leaves. |
| Paksha | The translator's note to BPHS 27.10-11 classes a dark-half Moon as malefic. | We treat it as benefic, because the reference does and is self-consistent with its own aspect treatment. This is a documented disagreement with the cited note, not an oversight. |
| Drik | BPHS 26.6-12 gives the aspect curve; 27.19 gives the assembly. | The benefic/malefic classification of the Moon and Mercury was derived empirically from reference rows rather than from a general planet-nature rule. |
| Hora | BPHS 27.13 awards strength to the lord of the birth hora but does not settle how the hora index is derived. Both 24 equal parts of sunrise-to-sunrise and a separate twelve-fold split of day and night are documented in the tradition. | 24 equal parts of sunrise to the next sunrise. This is not arbitrary: on the held fixture the two methods select DIFFERENT lords - equal parts gives the Sun, the day/night split gives Venus - and the reference reads the Sun. One chart cannot settle it universally, so it is listed here as a selected convention. |
Cheshta belongs on this list too, and is described separately below because its lineage is the one that rests on a printed edition rather than on our reference.
Sthana Bala (positional). Five parts. Uccha measures the arc from the planet’s deep debilitation point, so it peaks at deep exaltation. Saptavargaja scores its dignity across seven charts - the rasi, hora, drekkana, saptamsa, navamsa, dwadasamsa and trimsamsa - which is why this one component needs seven divisional engines behind it. Ojayugma rewards odd or even sign placement by planet nature, Kendradi rewards angular houses over succedent and cadent, and Drekkana rewards the third of the sign that matches the planet’s group.
Dig Bala (directional). Each planet has a direction where it is weakest - the Sun and Mars at the fourth, Jupiter and Mercury at the seventh, the Moon and Venus at the tenth, Saturn at the ascendant. Dig Bala is the shorter arc from the planet to that weak point, divided by three, so it maxes at 60 virupas exactly opposite.
Kala Bala (temporal). The busiest group, and the one that makes birth time matter. Paksha reads the lunar fortnight; Tribhaga splits day and night into thirds with a lord each; Vara gives the weekday lord 45 virupas; Hora gives the planetary hour’s lord 60; Masa and Abda hand strength to the lords of the month and the year; Ayana reads the planet’s declination. Nathonnatha, which measures distance from midnight or noon, is the one we withhold.
Cheshta Bala (motional). Strength from apparent motion, computed from the planet’s mean and true positions. The Sun and Moon score zero here by BPHS 27.18 - the text assigns the Sun’s Cheshta to its Ayana Bala and the Moon’s to its Paksha Bala, both already counted inside Kala, so adding them again would double-count.
Naisargika Bala (natural). A fixed ladder, identical in every chart: the Sun 60, the Moon 51.43, Venus 42.86, Jupiter 34.29, Mercury 25.71, Mars 17.14, Saturn 8.57. It is exact by construction, being simply sixty times k over seven.
Drik Bala (aspectual). The net of graded aspects the other six planets cast, benefics adding and malefics subtracting, divided by four. This is the only component that goes negative.
Shadbala means 'six strengths'. It is the Brihat Parashara Hora Shastra's system for measuring how much strength each of the seven classical planets carries in a birth chart, assembled from six separate sources: Sthana Bala (positional), Dig Bala (directional), Kala Bala (temporal), Cheshta Bala (motional), Naisargika Bala (natural) and Drik Bala (aspectual). Each source is computed in virupas and the classical method then adds them into a total. This tool computes and shows the six sources; it does not add them, and the reason is explained below.
A virupa (also called a shashtiamsa) is the unit Shadbala is measured in. Sixty virupas make one rupa, and the classical required-strength table is stated in rupas. Most individual components top out at 60 virupas, which is why you will see values clustering under that number - but there are two deliberate exceptions in the classical scheme, and this tool shows them as they are rather than clipping them. The Sun's Ayana Bala is doubled, so it can reach 120. The Moon's Paksha Bala is doubled in its Kala form, so it can reach about 120 as well. Every figure on this page is in virupas.
This tool will not tell you, and that is deliberate rather than a missing feature. Ranking planets requires a Shadbala TOTAL, and a total is only as trustworthy as its weakest component. Four of ours are not yet at the accuracy standard the rest of the stack holds to - Nathonnatha, exact Ayana, Graha Yuddha and Cheshta - so any ranking we printed could reorder two planets on the strength of an error we cannot bound. We would rather show you six honest columns than one confident-looking league table. If you want a numeric per-planet reading today, our Ashtakavarga calculator gives each planet its bindu scores across the signs by a different classical method, one we compute end to end.
Because our own rule is that a total stays null until every required component reaches parity with our reference implementation, and four do not. Nathonnatha has a known, unresolved, time-dependent deviation - the largest in the stack, reaching 4.028 virupas at the times we have measured. Ayana is approximate, with a maximum observed deviation of 0.36 virupas across our held validation set. Graha Yuddha is screened for by longitude only and its correction is not computed, and we hold no verbatim source for the orb, the victor rule or the evaluation order. Cheshta follows a source-prescribed convention that reproduces our reference to within about 0.2 virupas but is not parity-grade. We deliberately do not quote a combined figure for what a total would be wrong by: the deviations are not simultaneous, they do not share a sign, and the Yuddha term is unquantified, so any single number would be a guess wearing a decimal point. The per-component figures above are what we can actually stand behind.
Sthana Bala is positional strength, itself made of five parts - Uccha (distance from the planet's deep debilitation point), Saptavargaja (its dignity across seven divisional charts), Ojayugma (odd/even sign placement), Kendradi (angular, succedent or cadent house) and Drekkana (which third of the sign it occupies). Dig Bala is directional strength, measuring the planet's arc from the point where it is weakest. Kala Bala is temporal, and covers the lunar fortnight, day and night, the thirds of day and night, the weekday, the hora, the month and the year lords, plus the solar hemisphere. Cheshta Bala is motional strength. Naisargika Bala is a fixed natural ladder from the Sun down to Saturn. Drik Bala is the net of aspects the other planets cast on it.
Because we know its value is wrong and we do not know by how much on your chart. Nathonnatha measures a planet's strength by how far the birth sits from midnight or noon, and the epoch our construction measures from does not reproduce our reference. On the fixture we test against, the deviation runs from about -1.9 to about +4.0 virupas depending on the birth time, so it is not a fixed offset we could subtract out - it moves with the clock. Four candidate models have been tested and rejected. Printing a number we know to be wrong, in a table where every other number carries a stated accuracy, would be the dishonest option; we show the gap instead and put the measurements in the methodology panel.
Each component carries its own class and the maximum deviation we measured for it, listed in the accuracy table on this page. Most sit within a few hundredths of a virupa. Two important caveats travel with those figures. First, a validation on one or two charts is not universal parity, so the coverage column tells you which held charts each class was established on. Second, our reference implementation prints several of its bars to one decimal place, so our deltas bound the distance to a DISPLAYED value; its unrounded internal value could sit about 0.05 virupas either side, and that uncertainty sits on top of our figure rather than inside it. We do not claim a bound against its internal values, because establishing one needs unrounded output we do not have.
A graha yuddha is a 'planetary war', classically read when two of the five starry planets come very close together. If two of yours are within one degree of longitude, this tool says so. That is a screening result and not a determination: the check compares longitudes only, while a real close approach is two-dimensional, and we hold no sourced orb - the classical readings are not even the same test, since 'in the same degree' and 'within one degree' mean different things. Equally, no warning does not certify that your chart is free of graha yuddha. Nothing about the warning changes any number on the page; the classical war correction needs a Shadbala total, which this page does not produce.
No, and this tool makes no prediction of any kind. Shadbala is a computed quantity in a classical reference frame - it describes how the tradition scores a planet's strength from geometry and timing, not what will happen in your life. This page offers no remedies, no gemstones, and no rituals, and a low value is not a diagnosis of anything.
The structure of each component follows Brihat Parashara Hora Shastra chapters 26 and 27 in the R. Santhanam translation, consulted through a web transcription that carries no edition and no page number - so we say the components are traceable to that transcription rather than verified against print. The verses do not settle every piece of arithmetic, though. Five conventions were selected by matching the reference implementation we validate against rather than read off the text: the Dig cusp definition, the six lower rungs of the Saptavargaja ladder, the dark-half Moon's Paksha classification (where we knowingly differ from the translator's note), the Moon and Mercury benefic/malefic rule inside Drik, and how the hora index is derived. Each is listed with its reasoning in the 'Where the verses stop and our choices begin' section above. Cheshta is different again, and has the strongest lineage on the page: the Sripathi formula with the Kedarnath Dutt tables as printed in B.V. Raman's 'Graha and Bhava Balas', 13th edition, chapter VI, articles 95 to 107. Planetary positions come from the same Meeus VSOP87 engine and Lahiri ayanamsa as our Kundli.
This page is the canonical surface for these terms: Shadbala, Shadbala calculator, Shadbal, Sthana Bala, Dig Bala, Kala Bala, Cheshta Bala, Naisargika Bala and Drik Bala. They all refer to the six-fold planetary strength system described above.