Your birth number and life path from a date, and your name number from a name — worked out in both the Chaldean and Pythagorean systems, with the value of every letter printed so you can check the sum.
The two systems disagree about most names. Any calculator that hands you one number is not telling you that. Nothing here predicts anything, and nothing here sells a remedy.
Because they are using different systems and usually not saying so. Chaldean maps letters by sound and never uses 9; Pythagorean maps them by position in the alphabet. They disagree about most names. This page computes both and tells you when they differ, which is most of the time.
The birth number is the day of the month you were born, reduced to a single digit. The life path uses every digit of the full date. Practitioners treat the first as temperament and the second as the longer arc.
Eleven, twenty-two and thirty-three. Both traditions treat them as significant and do not reduce them further. A calculator that silently turns 11 into 2 is giving you a different answer from the practitioner you will ask next, which is why they are preserved here.
No. It is one traditional lens among several and it is not a reason to accept or refuse anybody. For matching, the kundli and the conversation carry far more weight — and the honest thing is to say that on the page rather than in small print.
Practitioners usually use the name you are actually called by rather than a legal full name, on the reasoning that it is the name in use that matters. Try both — the page shows the working, so you can see exactly which letters moved the total.
For matching that carries real weight, use Guna Milan or the ten poruthams. Curious what your name says astrologically? Rashi and nakshatra by name.