How the calculations work

Planetary positions

Birth-chart positions are computed by a dependency-free engine that implements published analytical algorithms: Paul Schlyter's planetary theory (standard orbital elements) for the Sun, Moon and planets, and Jean Meeus's algorithms for sidereal time. Positions are converted to the sidereal (Vedic) zodiac with the Lahiri ayanamsa.

The Moon's nakshatra and pada, the rashi, and the lagna (ascendant) are derived from these positions. Birth-place coordinates feed the ascendant and house calculations, and the UTC offset converts local birth time to universal time.

Validation against NASA JPL ephemerides

The engine was validated against NASA JPL ephemerides (DE421/DE441) across 41 test dates from 1950 to 2030. Maximum absolute errors found:

The classical scoring tables

Guna Milan follows the classical Ashtakoota system: eight kootas worth 36 points in total. The scoring tables are frozen — they do not change between releases, and every result page can be re-checked against them:

Directional kootas (Varna, Vashya) are read with Person 1 in the traditional bride's position and Person 2 in the groom's, as the classical texts prescribe.

Manglik dosha and its cancellations

Separately from the 36-point score, the calculator checks Manglik dosha for each person: if Mars stands in houses 1, 2, 4, 7, 8 or 12 counted from the rising sign (Lagna), the Moon, or Venus, the chart is flagged Manglik. The classical texts then list cancellations — conditions under which the dosha is treated as nullified — and the calculator applies them automatically:

• Mars in its own sign (Aries or Scorpio), or exalted (Capricorn).
• Sign-specific exceptions: Mars in the 2nd in Gemini or Virgo, in the 7th in Cancer, in the 8th in Sagittarius or Pisces, or in the 12th in Taurus or Libra.
• Jupiter or Venus sharing Mars's house, or aspecting Mars (Jupiter's 5th/7th/9th aspect, Venus's 7th).
• Both partners Manglik — tradition treats this as mutually cancelled.

Depending on how many of the three reference points flag Mars, a chart is graded Anshik (partial), Madhya (medium) or Purna (full) Manglik. A one-sided dosha is traditionally the point most families discuss with an astrologer.

A worked example

The frozen regression case, animated: Aarav — 14 Feb 1990, 10:30 AM, Mumbai — and Diya — 22 Aug 1992, 6:15 PM, Delhi. Watch what the calculator does with two birth moments.

Privacy

Every calculation runs in your browser. Birth details are never uploaded, stored on a server, or sent anywhere — the share link carries the inputs inside the URL itself, and saved matches live only in your browser's local storage.