How the prediction works
First the calculator finds the planets that signify marriage in your chart: the lord of the 7th house, any planet in the 7th, Venus, Jupiter (weighted more heavily in a woman’s chart), the Darakaraka, and the lords of the 2nd and 11th houses. Each one’s role is listed in the result.
Then it walks through your Vimshottari mahadasha and antardasha periods from marriageable age to 42 and scores each one by how strongly its two lords signify marriage. Within each period it checks every month for the double transit: Jupiter and Saturn both influencing the 7th house, the 7th lord’s sign or the 7th from the Moon. Months with the double transit score higher.
Reading the windows
A strong window has both dasha lords signifying marriage and the double transit active for a good part of it. A promising one has the antardasha lord signifying marriage. The strongest ages are the years where those windows cluster. If a window has passed, the next one from today is shown separately.
The chart factors section lists the classical delay factors, such as Saturn aspecting the 7th house or the 7th lord in the 6th, 8th or 12th, and the supporting ones, such as Jupiter aspecting the 7th. They do not change the scores, but they indicate whether the earlier or the later windows deserve more weight.
Why the birth time matters
The 7th house and its lord come from the ascendant, which changes sign roughly every two hours. A birth time that is off by an hour can move the 7th house to a different sign and change the whole list of significators. If you are unsure of the time, treat the result as indicative, or rectify the time first.
What this calculator does not do
It does not read the Navamsa, the Upapada or KP cusps, and it cannot know your circumstances. It shows the periods in which classical timing rules point most strongly to marriage, with the reasons, so you can judge them yourself or take them to an astrologer.