Guide
How Vimshottari dasha works
Vimshottari divides a 120-year cycle among nine planetary lords. The Moon's sidereal lunar mansion selects the first lord, and its progress through that mansion determines the balance remaining at birth. Subperiods divide each major period proportionally; a published date requires explicit birth inputs and a stated calendar convention.
Draft · specialist source review requested
How is the first period found?
Divide the sidereal zodiac into 27 equal lunar mansions. Each spans 13 degrees and 20 arcminutes. Starting with Ashwini, repeat Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury. If the Moon has traversed fraction f of its mansion, the first balance is (1 − f) times that lord's years. [BPHS ch. 48.]
How are the nine allocations divided?
| Lord | Full years | Major-period page |
|---|---|---|
| Ketu | 7 | Ketu mahadasha |
| Venus | 20 | Venus mahadasha |
| Sun | 6 | Sun mahadasha |
| Moon | 10 | Moon mahadasha |
| Mars | 7 | Mars mahadasha |
| Rahu | 18 | Rahu mahadasha |
| Jupiter | 16 | Jupiter mahadasha |
| Saturn | 19 | Saturn mahadasha |
| Mercury | 17 | Mercury mahadasha |
How are antardashas calculated?
Multiply the major-period allocation by the subperiod allocation and divide by 120. Begin the subperiod cycle with the major-period lord. An exact fraction can be converted to days only after selecting a days-per-year convention. [BPHS ch. 53.]
For a synthetic Venus major period, the Venus subperiod is 20 × 20 / 120 = 10/3 years. That fraction is exact; describing it as a dated calendar interval without a starting instant would not be.
Why might my dates differ?
Birth-time uncertainty, ayanamsa, lunar longitude, and year length affect boundaries. This content does not choose a hidden default or borrow private chart dates.
Does a period cause an event?
That is a traditional interpretive claim, not an established scientific mechanism. A period label should not overrule evidence, consent, or professional advice.
How does this compare with Western timing?
Western astrology often uses transits and progressions; Vimshottari assigns a sequence from the natal Moon. Both traditions have personality and timing techniques, but these clocks should not be merged without explanation.
Read the yoga directory, house-lord directory, and glossary.
Classical reference
BPHS ch. 48 and 53 in the checked numbering. Explanations and the worked fraction are original; no translation is quoted.
Updated 2026-10-13. Educational preview; read alongside the whole chart.
Where can I explore the chart factors?
How we calculate
Is astrology a guarantee of what will happen?
No. These calculations locate celestial bodies; astrology is a reflection and timing tradition, not evidence of guaranteed health, financial or relationship outcomes.
How are these results calculated?
Positions come from Astronomy Engine, an open-source astronomy library, and are checked against Swiss Ephemeris in our methodology tests. Western readings use the tropical zodiac; Vedic readings subtract the Lahiri ayanamsa. Terms are defined in the glossary.
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