How does kundli matching for marriage work?
The eight kootas are Varna, Vashya, Tara, Yoni, Graha Maitri, Gana, Bhakoot and Nadi. They ask practical things in old language: do the temperaments agree (Gana), will the two lead or follow well (Vashya), are their constitutions compatible (Nadi, the heaviest at eight points), do the Moons sit in friendly signs (Bhakoot), and so on.
The tests carry different weights, from 1 point for Varna up to 8 for Nadi. The two heaviest are Nadi at 8 points and Bhakoot at 7.
Two tests carry a dosha, a flaw, when they fail: Nadi and Bhakoot. A failed Nadi is what families ask about most, and in the classical rules it is also the one most often cancelled. Those rules cancel either dosha in some cases, for example when both Moon signs share a ruling planet, which is where a score alone stops being useful.
What the 36 points do not measure: the seventh house of each chart, the state of Venus and Mars, Mangal dosha compared between the two, and the dasha periods each person would be living through when the marriage would happen. Those are the difference between a number and a reading.
The free score is below. It is the same count every matching site gives. The reading of what the score cannot see is what Horoskope adds: with Pro, or the one-time match unlock, the app reads the seventh houses, Venus and Jupiter, Mangal dosha compared, and the periods each person is in.
The page that does this for you: Kundli matching calculator.