How We Calculate Your Kundli

1. Planetary positions come from the Swiss Ephemeris

We calculate where every graha actually stood in the sky at the moment you were born using the Swiss Ephemeris, the same astronomical library that professional astrology software has relied on for decades. It is not a lookup table or an approximation from your date alone. Given your exact birth moment and coordinates, it returns positions far more precisely than Vedic astrology needs — the boundaries that matter, like the edge of a nakshatra pada, are measured in whole degrees, while the ephemeris resolves to a tiny fraction of one.

2. We use the sidereal zodiac with the Lahiri ayanamsa

Vedic astrology uses the sidereal zodiac, which is measured against the fixed stars. Western astrology uses the tropical zodiac, measured against the equinox. Because the Earth wobbles slowly on its axis, these two have drifted apart over the centuries. The gap between them is called the ayanamsa, and it is currently around 24 degrees.

Which ayanamsa you pick genuinely changes the answer, so it is worth stating plainly: we use Lahiri, also called Chitrapaksha. It is the value adopted by the Indian Calendar Reform Committee and the standard used by the Government of India, which makes it the most widely accepted choice in Indian astrology. Your chart also displays the exact ayanamsa applied to your birth date, so nothing is hidden.

This is the reason your Vedic sun sign is often the previous sign from the Western one you already know. Neither is wrong. They are measured from different starting points.

3. Houses are whole sign, the classical Parashari method

The sign containing your Lagna becomes the first house in its entirety, the next sign becomes the second house, and so on around the chart. There is no splitting of signs across house boundaries. This is the oldest and most widely used system in Vedic astrology, and it is what the classical texts assume. It also means a planet's house never depends on which of several competing mathematical house divisions a site happens to prefer.

4. Nine grahas, with the True Node for Rahu

We compute the Navagraha: Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Rahu and Ketu. Uranus, Neptune and Pluto are deliberately excluded, because classical Vedic astrology does not use them.

For the lunar nodes we use the True Node, the actual oscillating position of the point where the Moon's orbit crosses the ecliptic, rather than the Mean Node, which is a smoothed average. The two can differ by more than a degree, which is enough to move Rahu into a different nakshatra. Ketu is placed exactly 180 degrees opposite Rahu, as tradition requires.

5. Birth time is converted using historical timezone rules

This is where most free Kundli tools quietly go wrong, and it matters more than the choice of ephemeris. A birth time is meaningless without knowing the offset from Universal Time that was actually in force at that place on that date.

We resolve your birth place to coordinates, derive the timezone from those coordinates rather than from the country name, and then apply the offset and daylight saving rules that were in effect on your birth date — not the rules in effect today. Timezones and daylight saving have changed repeatedly across the world, and using today's rules for a birth decades ago can shift a chart by a full hour. An hour is enough to change your Lagna entirely.

6. Vimshottari Dasha runs from the Moon's nakshatra

The Vimshottari system divides life into a fixed 120 year cycle of planetary periods. Which planet's period you are born into is determined by the nakshatra your Moon occupied at birth, and how much of that first period has already elapsed is set by exactly how far the Moon had travelled through that nakshatra. We calculate that fraction rather than rounding it, then run the full sequence forward so your timeline reflects your real starting point.

7. Mangal Dosha follows the classical rule, with exceptions

Mars is treated as causing Mangal Dosha when it occupies the 1st, 2nd, 4th, 7th, 8th or 12th house counted from your Lagna. We also check the classical cancellations: the dosha is considered mitigated when Mars sits in its own sign, Aries or Scorpio, or in its sign of exaltation, Capricorn. Our calculator shows you the house placement and the exception status separately, rather than reducing everything to a single alarming verdict.

8. The chart is mathematics; the reading is interpretation

We think this distinction deserves to be stated openly. Everything above is deterministic: run the same birth details twice and you get identical numbers, every time. The conversational reading is different. Our AI astrologer receives your computed chart and interprets it using the significations found in classical Vedic literature. Interpretation is an act of judgement, not calculation, and reasonable astrologers disagree. Treat the numbers as facts and the reading as a perspective.