Vimshottari Dasha Calculator

Written by Orbitarot · Sources: our own engine, positions checked against NASA JPL Horizons (method); place data GeoNames (CC BY 4.0); interpretations our own · Updated October 7, 2026

How the Vimshottari system works

Vimshottari means "one hundred and twenty". The system gives each of the nine grahas a fixed number of years, in a fixed order, adding up to 120:

The sequence does not start with Ketu for everyone. It starts with the lord of the nakshatra your Moon was in at birth, and the first period is only partly left, in proportion to how much of that nakshatra the Moon still had to travel.

A worked dasha example

Say your sidereal Moon was at 15 degrees Taurus. That is in Rohini (10 degrees to 23 degrees 20 minutes Taurus), whose lord is the Moon. The Moon had covered 5 of Rohini's 13.33 degrees, 37.5%, so 62.5% was left. The Moon mahadasha lasts 10 years, so at birth 6 years and 3 months of it remained. Then come Mars (7 years), Rahu (18), Jupiter (16), Saturn (19), Mercury (17), Ketu (7), Venus (20) and Sun (6), each starting where the last one ended.

Each mahadasha is split into nine antardashas (sub-periods) in the same order, starting with its own planet. Each sub-period's length is the product of the two planets' years divided by 120. In the Rahu mahadasha, for example, the Rahu-Jupiter antardasha lasts 18 x 16 / 120 = 2.4 years, about 2 years, 4 months and 24 days. The calculator also goes one level further, to pratyantardashas.

Why dates differ between calculators

• The Moon's exact position. The Moon moves about 13 degrees a day. A birth time off by one hour moves the Moon by about half a degree, which changes the balance of the first dasha by months, and shifts every later date by the same amount.
• The ayanamsa. We use Lahiri. A different ayanamsa moves the Moon's sidereal position and with it every date.
• The length of a year. Some software counts a dasha year as 365.25 days, some as the sidereal solar year (about 365.256 days), and some as 360 days (the savana year). Over decades the difference adds up to months. The calculator shows which it uses and lets you change it.

If two calculators disagree by a few weeks, one of these is the reason. A difference of years usually means a different birth time or a tropical Moon used by mistake.

What the periods are read as

In Jyotisha the planet running the mahadasha is read as the main theme of that span of life, colored by its sign, house and strength in your kundli, and the antardasha as the sub-theme. A Jupiter period is traditionally associated with learning and teachers, a Saturn period with discipline and patience, a Venus period with relationships and the arts. These are symbolic readings within a tradition. We do not use dashas to predict marriage, illness, money, legal events or death, and no period is simply good or bad.

Questions

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