Vedic Planetary Period Calculator
Arithmetic to the day, which is why nothing here is guessed.
Vedic astrology times your life in planetary periods rather than predictions. Vimshottari Dasha is the traditional system used here: it divides 120 years into nine periods and subdivides them five levels deep, and every boundary follows arithmetically from your Moon's nakshatra.
Which period you are in, and when it changes
A dasha is a span of time assigned to a planet. Vimshottari — the main Vedic timing system — divides 120 years into nine unequal periods: Ketu 7 years, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19, Mercury 17. The order never varies and it cycles.
Your starting point is set by your Moon's nakshatra. Each nakshatra has a ruling planet, and that planet's period is the one you were born into — with the portion already elapsed determined by how far the Moon had travelled through the nakshatra. Everything after that follows to the day.
It answers 'when', which is the question most people actually arrive with. A birth chart describes tendencies; a dasha describes the chapter you are currently in. Arivyah computes all five levels — mahadasha, antardasha, pratyantardasha, sookshma and prana — with real dates.
Calculate your Vimshottari Dasha periods
A 120-year cycle of planetary periods, entered at the point your Moon's nakshatra sets. These are real dates, not a forecast.
What it is called
Vedic astrology reached the English-speaking world through several routes, so most concepts here carry a Sanskrit name and one or two translations. They are the same thing.
- Dashaalso called planetary period
- A span of time ruled by one graha. The system as a whole is a way of saying which chapter of life you are in, and when it changes.
- Vimshottarialso called the 120-year cycle
- The most widely used dasha system, named for its total: vimshottari means 120. Nine planets, unequal periods, fixed order.
- Mahadashaalso called major period
- The top-level period, from 6 years (Sun) to 20 (Venus). The one people mean when they say 'I'm in my Saturn dasha'.
- Antardashaalso called bhukti, sub-period
- A subdivision of a mahadasha, nine per period. Most practical timing reads the mahadasha and antardasha together.
Your Vimshottari Dasha
Vimshottari Dasha is the traditional Vedic system used here to calculate planetary periods, and it is the one nearly all modern Vedic practice runs on. Vimshottari means one hundred and twenty: the full cycle it describes is 120 years long.
There are other dasha systems — Ashtottari, Yogini, Kalachakra and a dozen more — and they answer the same question with different arithmetic. Arivyah computes Vimshottari because it is the system a Vedic reading almost always means when it refers to your current period, and naming it lets you check the figures against any other source that uses it.
The nine periods, and where yours starts
The lengths are fixed, they never vary, and they add to exactly 120 years: Ketu 7, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19, Mercury 17.
The order is fixed too, and it is the same order as the ruling planets of the 27 nakshatras — Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, repeating three times across the circle. That is not a coincidence; it is why the two systems are the same system seen from two angles.
Your entry point is set by where your Moon was. Find the nakshatra it occupied, take that nakshatra's ruling planet, and that is the mahadasha you were born into. Then measure how far through the nakshatra the Moon had gone: if it was a third of the way through, a third of that period had already run before you were born, and you got the remaining two thirds. Everything after that is the fixed sequence, and the dates follow arithmetically to the day.
Five levels down
A twenty-year Venus mahadasha is too coarse to be useful on its own, so the system subdivides — each level using the same nine planets in the same order, weighted by the same proportions.
- chevron_rightMahadasha — 6 to 20 years. The overall chapter. Arivyah reports yours with real start and end dates.
- chevron_rightAntardasha — months to a few years. Nine per mahadasha. Most working timing is read at this level — the combination of the two is what an astrologer usually means by 'your current period'.
- chevron_rightPratyantardasha — weeks to months. Useful for narrowing a year down to a season.
- chevron_rightSookshma dasha — days to weeks. Rarely used outside close timing questions.
- chevron_rightPrana dasha — hours to days. The finest level the system defines, and the one most sensitive to a wrong birth time — a few minutes of error makes it meaningless.
Why an AI cannot make these up
Dasha dates are the clearest case on this site for the difference between a calculation and a plausible-sounding sentence, so it is worth being explicit.
Your mahadasha boundaries are arithmetic. They depend on your Moon's exact sidereal longitude, the nakshatra it falls in, the fraction of that nakshatra already elapsed, and the fixed period lengths. Given those, the dates follow to the day, and two correct implementations will agree.
A language model asked to produce them without that arithmetic will produce dates. They will look right — plausible spans, sensible planets, confident phrasing — and there is no way for a reader to tell they are invented. This is the specific failure Arivyah is built to avoid: the ephemeris and the dasha arithmetic run first, in Python, and the model receives the computed timeline as input. It explains what a Rahu period is traditionally held to mean. It is not permitted to decide when yours began.
Where to go next
Each of these reads a different part of the same birth data, so once one is computed the rest need nothing more from you.
Find the nakshatra your dasha starts from
The whole 120-year sequence follows from your Moon's nakshatra and its ruling planet.
Check your current planetary transits
Tradition reads transits against the dasha running underneath them, not on their own.
Check whether you are in Sade Sati
A Saturn transit, read differently depending on which dasha it lands in.
Generate your full birth chart
A dasha is read through that planet's condition in your chart — sign, house, strength and aspects.
Calculate your Moon sign
The position the entire dasha calculation depends on.
Ask about your current period
The AI reads your computed timeline. It cannot invent a date it was not given.
Questions
What is a dasha?add
A period of time assigned to a planet. Vedic astrology's main timing system, Vimshottari Dasha, divides a 120-year span into nine unequal planetary periods, and the one you are in is held to colour the chapter of life you are living. It is the answer to 'when', which is the question most people actually arrive with — a birth chart says what your tendencies are, a dasha says what season you are in.
How is my dasha calculated?add
From your Moon's nakshatra, not your sign. Each of the 27 nakshatras has a ruling planet, and that planet's period is the one you were born into. How far the Moon had already travelled through that nakshatra determines how much of the period had already elapsed at birth — so someone born at the start of a nakshatra gets nearly the full period, and someone born near the end gets only a remnant. Everything after that follows the fixed sequence.
How long is each period?add
They are fixed and unequal, and they total 120 years: Ketu 7, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19, Mercury 17. The order is always the same and it cycles, so after Mercury comes Ketu again. Because the total is 120 and a life is shorter, most people experience five or six mahadashas.
What is an antardasha?add
A subdivision. Each mahadasha is divided into nine antardashas, in the same planetary order and in proportion to the same weights, so a Rahu mahadasha of 18 years contains a Rahu antardasha, a Jupiter one, a Saturn one and so on. It subdivides again into pratyantardasha, then sookshma, then prana — five levels in all. Arivyah computes all five, though the top two are where most of the practical reading happens.
Does a bad dasha mean a bad period?add
Tradition is more careful than that. A dasha is read through the condition of that planet in your specific chart — its sign, its house, its strength, what aspects it. Saturn's period for someone with a well-placed Saturn is described very differently from the same period for someone whose Saturn is afflicted. There is no universally bad dasha, and any source that gives you one is not reading your chart.
How accurate does my birth time need to be?add
This is the calculation most sensitive to birth time on the whole site. The starting point depends on the Moon's exact degree within a nakshatra, and the Moon moves about half a degree an hour — which at the start of a long mahadasha can shift every subsequent boundary by months. An error of a few minutes is tolerable; an error of an hour is not, and the chart reports the degree so you can see how much precision you actually have.
How this is calculated
The arithmetic, and where it stops
The Moon's sidereal longitude is computed from Swiss Ephemeris data with the Lahiri ayanamsa. That gives the nakshatra, its ruling planet, and the fraction of the nakshatra already traversed — which sets the balance of the mahadasha remaining at birth. Every subsequent boundary is derived from the fixed period lengths, to the day.
All five levels are computed the same way, each subdividing its parent in the same nine-planet order and the same proportions. Nothing is estimated or rounded to a year.
This is the calculation most sensitive to birth time on the site: the Moon moves about half a degree an hour, and at the start of a long period a small error propagates months forward. The chart reports the Moon's degree so the precision you actually have is visible rather than hidden.
The dates are arithmetic and checkable. What a planetary period is said to bring is classical interpretation, read through that planet's condition in your chart, and presented as tradition rather than as prediction.
Positions are astronomy and can be checked against any ephemeris. What a position is said to mean is astrological interpretation, and this site presents it as tradition rather than as established fact. How every chart here is calculated.
See your timeline with real dates
Your current mahadasha and antardasha, the full sequence with start and end dates, and the planetary conditions each period is read through.