Vimshottari Dasha: The 120-Year Planetary Period System

How mahadasha, antardasha and pratyantardasha are calculated and read

Updated 8 October 2026

Vimshottari dasha is the most widely used timing system in Vedic astrology. It divides a notional human lifespan of 120 years among the nine planets in a fixed order, and your birth nakshatra decides which planet’s period you begin life in. While transits show what is happening in the sky now, dashas show which planet’s themes are “switched on” in your own chart. This guide explains the cycle, the maths and how astrologers read it.

What does “Vimshottari” mean?

“Vimshottari” comes from vimshottari, meaning “one hundred and twenty”, being the sum of the planetary periods. The system is described in the classical Parashari tradition and is one of many dasha systems (such as Ashtottari and Yogini), but it is the default in most modern practice, especially for charts where the Moon’s nakshatra is the natural starting point. The word dasha simply means “period” or “state”, and the lord of the running period is called the dasha lord.

The nine planets and their years

The nine grahas rule fixed numbers of years, always in the same sequence. Whichever planet rules your birth nakshatra opens the cycle, and the rest follow in order, repeating after Mercury returns to Ketu.

The longest period is Venus (20 years) and the shortest is the Sun (6 years). Because the cycle is fixed, you can know the sequence of your future periods the moment you know which one you start in.

Which nakshatra starts which dasha?

There are 27 nakshatras and 9 planets, so each planet rules three nakshatras, spaced nine apart. The Moon’s nakshatra at birth (the janma nakshatra) gives the first dasha lord.

The pattern is simple: starting from Ashwini, the lords run Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, then repeat for the next nine nakshatras, and again for the last nine. If you are unsure of your nakshatra, our nakshatra guide lists all 27 and the degrees they cover.

Mahadasha, antardasha and pratyantardasha

Dashas are nested like the hands of a clock:

• Mahadasha (MD): the major period of one planet (6 to 20 years).
• Antardasha (AD, also bhukti): a sub-period of another planet within the mahadasha, lasting months to a few years.
• Pratyantardasha (PD): a sub-sub-period within an antardasha, lasting weeks to months.
• Finer levels (sookshma, prana, dehas) exist but are rarely needed outside of event-timing work.

The balance of dasha at birth: a worked example

You are rarely born exactly at the start of a nakshatra, so the first mahadasha is only partly left. The calculation uses how far the Moon has travelled through its nakshatra.

1. Find the Moon’s sidereal longitude at birth. A nakshatra spans 13°20′ (13.3333°).
2. Find the fraction of the nakshatra already crossed.
3. The balance (remaining) = (1 − fraction crossed) × the dasha lord’s total years.

Example. Suppose the Moon is at 8°00′ Leo, which is 128°00′ from 0° Aries. Magha runs from 120°00′ to 133°20′. The Moon has travelled 8°00′ through it, and 8 ÷ 13.3333 = 0.6 of the nakshatra is done, leaving 0.4. Magha is ruled by Ketu (7 years), so the balance at birth is 0.4 × 7 = 2.8 years, about 2 years, 9 months and 18 days of Ketu dasha. At the end of that period the 20-year Venus mahadasha begins, followed by the Sun (6), Moon (10), and so on. A person born with the Moon just entering a nakshatra would have nearly the whole mahadasha ahead; one born at the very end of a nakshatra would start with only days or months remaining.

Software performs this precisely down to seconds, including the choice of year length (most use 365.25 days; some traditions use a 360-day “savana” year), which can shift dates by a few weeks. This is why two programmes may show slightly different change-over dates.

How antardashas are calculated

Within a mahadasha, every planet gets a share proportional to its own years out of 120. Sub-periods always start with the mahadasha lord itself and then follow the same Vimshottari sequence.

Formula: antardasha length (in years) = (mahadasha years × antardasha lord’s years) ÷ 120.

Example: Saturn mahadasha (19 years).

• Saturn–Saturn: 19 × 19 ÷ 120 = 3.008 years
• Saturn–Mercury: 19 × 17 ÷ 120 = 2.692 years, about 2 years, 8 months and 9 days
• Saturn–Ketu: 19 × 7 ÷ 120 = 1.108 years
• Saturn–Venus: 19 × 20 ÷ 120 = 3.167 years

Adding all nine antardashas in a Saturn mahadasha gives 19 years. Pratyantardashas use the same rule one level down: pratyantardasha length = (MD years × AD years × PD years) ÷ 14,400. For instance, Saturn–Mercury–Ketu lasts 19 × 17 × 7 ÷ 14,400 ≈ 0.157 years, about 57 days. Because a dasha chain is a sequence of planets, we describe a period as “Saturn–Mercury–Ketu” in that order.

What each mahadasha tends to emphasise

These are general tendencies. The actual results depend on the planet’s house, sign, dignity, aspects and the houses it rules in your chart.

How to read a dasha

A skilled reading follows a rough order. First, look at the dasha lord’s placement: its house, sign and dignity (exalted, own sign, friendly, debilitated). A well-placed lord generally delivers its promises; a weak one delivers them with effort. Next, see which houses it rules: the mahadasha tends to energise those themes, for example a lord of the 10th brings career matters forward. Look also at the planets it conjoins or aspects, and at the sign position of the nakshatra it occupies.

Then examine the antardasha lord’s relationship with the mahadasha lord: friends tend to give smoother sub-periods, enemies more friction. Finally, cross-check with transits such as Sade Sati and Jupiter’s movement; a good dasha with a supportive transit is considered the strongest combination for events like marriage, career change or property. When reading relationships in particular, the Navamsa chart is consulted alongside the Rashi chart. For a plain-language reading of every pairing, from Ketu–Ketu to Mercury–Saturn, see our guide to all 81 mahadasha and antardasha periods.

You do not need to calculate any of this by hand: the Navagraha app lists your complete Vimshottari timeline with the current mahadasha, antardasha and pratyantardasha for free.

Dasha sandhi: the junctions

Dasha sandhi refers to the changeover period between two mahadashas (and, to a lesser degree, antardashas). Classically the last portion of one dasha and the first portion of the next are seen as times of transition: priorities, environment or roles can shift quickly because two planets with different natures hand over control. This is especially noted when the outgoing and incoming lords are mutual enemies or sit in 6th/8th relation to each other. It is generally a time for care rather than alarm.

Common misconceptions

• “Rahu or Saturn dasha means suffering.” Every planet can give good results; a well-placed Rahu or Saturn can bring great progress.
• “Dasha predicts exact events.” It indicates favourable and unfavourable windows and themes; it does not remove free will.
• “The Moon sign decides the dasha.” The nakshatra of the Moon decides the starting lord, not the sign.
• “Everyone has the same lifespan of 120 years.” The 120 years is a symbolic cycle used for timing, not a prediction of longevity.

Why accurate birth time matters

The Moon moves about 13 degrees a day, or roughly half a degree an hour. An error of a few hours in birth time shifts the Moon’s fraction through its nakshatra, and therefore the balance at birth, by months or even years, and can in some cases change the nakshatra itself. If you are unsure of the time, see our Kundli guide for how astrologers rectify it.

The dasha lord by house: a quick reading guide

The house in which the mahadasha lord sits gives a quick sense of where the period’s energy goes. These are traditional pointers, to be combined with sign, dignity and the houses the planet rules:

• In the 1st, 5th or 9th: the period often favours self-development, learning, children, fortune and guidance.
• In the 2nd or 11th: finances, savings, family and networks are the focus.
• In the 3rd or 6th: effort, skills, competition and service; results often come through hard work.
• In the 4th: home, property, vehicles, mother and inner peace take centre stage.
• In the 7th: marriage, partnerships and business associates.
• In the 10th: career, status and public responsibility.
• In the 8th or 12th: introspection, change, expenses, foreign connection or spiritual search; handled with care they can also bring deep growth.

Other dasha systems

Vimshottari is the most common but not the only system. Others include Ashtottari (108-year), Yogini (36-year), Kalachakra and the sign-based Chara dasha of the Jaimini school. Each has its own conditions of use. Vimshottari is traditionally preferred when the Moon is in a particular relationship to the ascendant, but in current practice it is used almost universally. For a first look at your own timeline, the nakshatra guide explains how the starting lord is chosen.

Frequently asked questions

Navagraha provides Vedic astrology for informational and reflective purposes only; it is not a substitute for professional advice.