Pillar A — How it works

Published 2026-04-28 · Updated 2026-06-18 · By Avinash Chandan, Founder, Navamsha

How Vimshottari Dasha Is Calculated (With a Working API Example)

Vimshottari Dasha is a 120-year cyclical system in Vedic astrology that divides a person's life into planetary periods (Mahadashas) and sub-periods (Antardashas), used to time when specific life events are likely to manifest.

It is the most widely used dasha system in Parashari Jyotish — the first calculation most astrologers run after generating a birth chart. This guide walks through the math step by step, then shows how to fetch the same result from the Navamsha Dasha API at /apis/dasha on the 10,000 free calls/month tier.

What Vimshottari Dasha actually measures

Vimshottari assigns each of the nine grahas a fixed number of years. Together these add up to exactly 120 years — the traditional maximum human lifespan in this system.

These nine periods always occur in the same fixed sequence (Ketu → Venus → Sun → Moon → Mars → Rahu → Jupiter → Saturn → Mercury → back to Ketu), repeating if a person's life span exceeds 120 years.

Step 1: Find the starting point — birth Nakshatra

The calculation does not start from your birth date. It starts from the Moon's Nakshatra (lunar mansion) at the moment of birth.

Each of the 27 Nakshatras is ruled by one of the nine grahas in the same Ketu-Venus-Sun-Moon-Mars-Rahu-Jupiter-Saturn-Mercury sequence, repeated three times. Whichever graha rules your birth Nakshatra becomes your first Mahadasha lord.

Step 2: Calculate the balance of the first Mahadasha

You are not born at the exact start of a Nakshatra. The remaining portion determines how much of the first Mahadasha's full term you have left from birth.

Each Nakshatra spans exactly 13°20′ (13.333°). If the Moon is 9° into a Nakshatra ruled by Venus (20-year Mahadasha), the remaining 4°20′ represents the balance of the Venus Mahadasha still to run from the birth date.

Step 3: Lay out the full sequence

Once the balance of the first Mahadasha is known, the remaining eight Mahadashas are laid out in full length in the fixed sequence. The result is a complete 120-year timeline from birth.

Step 4: Calculate Antardashas (sub-periods)

Each Mahadasha is divided into nine Antardashas in the same fixed sequence, starting with the Mahadasha lord.

Within a Venus Mahadasha (20 years), the Venus-Venus Antardasha lasts about 3.33 years, while Venus-Saturn lasts about 3.17 years. Antardasha transitions are where birth-time precision matters most.

Getting this from a birth chart via API

The Navamsha Dasha API performs ephemeris lookup, Nakshatra boundaries, and fraction arithmetic in one call — backed by Swiss Ephemeris and deterministic Lahiri-ayanamsa Nakshatra lookup. Responses include engine metadata so you can audit ayanamsa, formula version, and node mode.

curl -X POST "https://api.navamsha.in/api/v1/dasha/vimshottari" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "year": 1995, "month": 8, "date": 15, "hours": 14, "minutes": 30, "seconds": 0, "latitude": 19.0760, "longitude": 72.8777, "timezone": 5.5, "settings": { "observation_point": "topocentric", "ayanamsha": "lahiri", "language": "en" } }'

import httpx

birth = {
    "year": 1995, "month": 8, "date": 15,
    "hours": 14, "minutes": 30, "seconds": 0,
    "latitude": 19.0760, "longitude": 72.8777, "timezone": 5.5,
    "settings": {"ayanamsha": "lahiri", "observation_point": "topocentric"},
}
resp = httpx.post(
    "https://api.navamsha.in/api/v1/dasha/current",
    headers={"X-API-Key": "YOUR_API_KEY"},
    json=birth,
)
dasha = resp.json()["output"]
print(dasha["mahadasha"])
print(dasha["antardasha"])

The response includes the full Mahadasha sequence with start/end dates, the current Antardasha, and engine metadata — so AI astrologer products can ground answers in verifiable calculation rather than generated guesses. Sign up at /getting-started for 10,000 free calls per month.

Building a Dasha-aware app? See /apis/dasha for the full Dasha & Timing API, or /apis/compatibility for Dasha-aware Gun Milan matching.