Dasha Calculator: Mahadasha, Antardasha, Pratyantardasha

Vimshottari Dasha is the most widely used timing system in Vedic astrology, spread across a 120-year cycle shared among the nine grahas: Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn and Mercury, each assigned a fixed number of years, from Ketu's 7 to Venus's 20.

Your specific starting point in this cycle depends on which nakshatra the Moon was in at your birth, and exactly how far through that nakshatra the Moon had travelled. This gives you a "balance of Dasha" at birth, some leftover years of your first Mahadasha before the sequence moves to the next planet in order.

Each Mahadasha is further divided into Antardashas of every planet in the same fixed sequence, and each Antardasha is divided again into Pratyantardashas. This three-layer system is how astrologers narrow a broad multi-year period down to a specific few-week window for a predicted event.

A user wanted to know the best few weeks in the next year to sign a property deal. His Mahadasha was Jupiter, generally good for growth and expansion, and inside it he was running a Mercury Antardasha, favourable for contracts and paperwork. Drilling down to Pratyantardasha, a Venus Pratyantardasha inside that Mercury Antardasha, roughly five weeks long, stood out as the most favourable short window, since Venus supports property and agreements. We gave him the exact start and end dates of that Pratyantardasha rather than a vague "sometime this year."

That is the value of going three layers deep: Mahadasha sets the mood, Antardasha narrows the theme, Pratyantardasha gives an actual calendar window.

This calculator is built by the AstroFuture AI team at BEONE DEAL. The Moon's position is calculated with the Swiss Ephemeris using True Moon and Lahiri ayanamsa, and the Dasha sequence follows the standard Vimshottari order and proportions laid out in Parashari texts. Before any change to the Dasha engine goes live, we check its output against established astrology software so your Mahadasha and Antardasha dates match what professional software would generate from the same birth details.

Dasha depends entirely on your Moon's nakshatra and exact degree at birth, which depends entirely on accurate birth time. If your time is off by even 15-20 minutes near a nakshatra boundary, your starting Mahadasha and its balance can shift, and every date downstream shifts with it. Check your Nakshatra first if you are unsure. Dasha also shows likely themes and windows, not certainties, the same period can play out differently depending on what that planet is doing in your D1 and D9 charts.

Suppose your Moon at birth is in Ashwini nakshatra, ruled by Ketu, and had travelled 5°20' out of Ashwini's full 13°20' span, meaning 40% of the nakshatra was already covered. Ketu's Mahadasha runs 7 years total, so 40% is used up, leaving 60% of 7 years, roughly 4.2 years, as your balance of Ketu Mahadasha from birth.

After that remaining 4.2-year Ketu period ends, the sequence moves to Venus (20 years), then Sun (6 years), Moon (10 years), and onward in the fixed Vimshottari order, each full Mahadasha further broken into 9 Antardashas proportional to the same 120-year ratio.

A Mahadasha sets the broad theme for years, but the specific Antardasha running inside it often decides what actually happens month to month. For example, someone in Jupiter Mahadasha, generally a growth-oriented period, going through a Saturn Antardasha might feel more delay, responsibility and slow progress than the outer Jupiter theme suggests.

This is why we always show all three layers together rather than just the Mahadasha, since reading Mahadasha alone can give a misleadingly simple picture of what a given month or year will actually feel like.