Vimshottari Dasha: How the 120-Year Cycle Is Calculated

The birth chart shows what life holds; the dasha shows when. Of the many dasha systems in Vedic astrology the most widely used is Vimshottari, whose full cycle is 120 years. Parashara names it the principal system for the present age.

The nine major periods

7 + 20 + 6 + 10 + 7 + 18 + 16 + 19 + 17 = 120. The periods run in this order, with Ketu following Mercury.

Which dasha at birth, and how much is left

Life begins in the dasha of the lord of the Moon's birth nakshatra. But the whole period is not available: as much of the nakshatra as the Moon has already crossed, that much of the dasha is already "spent".

The rule: a nakshatra is 13°20′ (800 minutes of arc). The balance of the dasha is in proportion to the part of the nakshatra still ahead of the Moon.

Example: at birth the Moon is at 15° Taurus. Rohini runs from 10° to 23°20′ Taurus, so the Moon has crossed 5° and has 8°20′ (500′) left. Rohini's lord is the Moon, whose dasha is 10 years. Balance = 10 × 500 ÷ 800 = 6.25 years, about 6 years 3 months. Then come Mars's 7 years, Rahu's 18, and so on.

Suvolagna's birth chart page does this calculation and lists the full dasha sequence.

Sub-periods (antardasha)

Each major period contains nine sub-periods in the same order, starting with the major period's own planet. Their length:

sub-period = major period years × sub-period planet's years ÷ 120

Saturn–Saturn = 19 × 19 ÷ 120 = 3.01 years, about 3 years. Saturn–Mercury = 19 × 17 ÷ 120 = 2.69 years, about 2 years 8 months. Sub-sub-periods (pratyantardasha) are found the same way.

How a dasha is judged

The dasha planet gives results according to its condition and the houses it rules. The key questions:

1. Which houses it rules: lords of kendras and trikonas usually give good periods; lords of the sixth, eighth and twelfth periods of strain.
2. Where it sits: placed in a good house, it opens the good side of what it rules.
3. Strength: exalted, own-sign or friendly planets give good periods; debilitated, combust or hostile ones more obstacles.
4. Yogas: a planet involved in a raja yoga or dhana yoga delivers that yoga in its period.
5. Transits: where the planets are transiting during the period fixes the timing of events more finely.

For Rahu and Ketu, look at their sign, their companions and where their sign lord sits.

A common mistake

Blanket claims such as "Saturn's dasha is always bad" or "Venus's dasha always brings happiness" are wrong. For Taurus and Libra lagnas Saturn is the yogakaraka, and its nineteen years can be the best of life. Where Venus rules the eighth house, its period calls for care with health and sudden obstacles. A dasha has to be read from one's own chart.