The ten poruthams
Dina counts the groom’s star from the bride’s and reads the nine taras. Gana compares temperament: Deva, Manushya or Rakshasa. Mahendra agrees when the count is 4, 7, 10, 13, 16, 19, 22 or 25. Stree Deergha wants the groom’s star well ahead of the bride’s, more than 13 counts. Yoni compares the animal of each star.
Rasi reads the distance between the two Moon signs. Rasi Adhipati asks whether their lords are friends. Vasya asks whether one sign holds the other in its sway. Rajju sorts the 27 stars into five groups from foot to head. Vedha names pairs of stars that afflict one another.
Rajju and Vedha are vetoes
If both stars fall in the same rajju, Rajju dosha is present, and each rajju carries its own concern: the head for the husband’s longevity, the neck for the wife’s, the navel for children, the waist for prosperity, the foot for separation. If the two stars are a vedha pair, Vedha dosha is present. Either one traditionally ends the match however many other poruthams agree, so the calculator never lets the count outweigh them.
How many poruthams should match?
With Rajju and Vedha clear, seven or more agreeing is uttamam, excellent. Five or six is madhyamam, the usual threshold. Fewer than five is adhamam, and most families would not proceed. A partial agreement, such as Stree Deergha between 7 and 13, counts as half. Many almanacs also single out five that should agree: Dina, Gana, Yoni, Rasi and Rajju, and the result shows those separately.
Porutham and Guna Milan
The two systems share their raw material: the birth stars, their ganas and yonis, and the Moon signs and their lords. This calculator reads those from the same tables as our 36 Guna Milan calculator, so Rasi porutham and Bhakoot always agree. Where the Tamil and North Indian conventions genuinely differ, the result states which rule was used.