What is calculated here
Numerology reduces a date of birth to a single number from 1 to 9 — and separately keeps the “master numbers” 11, 22 and 33, which aren’t reduced to one digit. The Life Path number comes from the full date, the Birthday number — from the day of the month alone, the Personal Year — from the date and the current year.
If you enter a name, you get three more numbers: Destiny (from all the letters), Soul (from the vowels) and Personality (from the consonants). Spelling matters — “Roman” and “Roman Romanovich Romanov” give different numbers, so write it the way you most often call yourself.
Why time and city aren’t asked for here
Because they affect nothing: numerology works with the digits of the date, not with the positions of the planets. Time and place are needed where the sky is calculated — in Human Design, the natal chart and Jyotish. Asking for them here would mean demanding data for the sake of looking precise.
How the main number is calculated
The Life Path number is calculated in parts: the day separately, the month separately, the year separately, and only then their sum. For example, June 15, 1975: day 1 + 5 = 6, month 6, year 1 + 9 + 7 + 5 = 22 — we don’t reduce it, it’s a master number; 6 + 6 + 22 = 34, 3 + 4 = 7. If you add all the digits of the date in a row, this date also gives 7, but that’s not always the case: roughly one date in eight gives a different answer, and the reason is always the master numbers.
Personal Year and name numbers
The Personal Year here changes on your birthday, not on January 1: until your birthday the previous cycle is in effect, and the result label shows the date it runs from. Name numbers are calculated by a letter table; a Latin name — by the Pythagorean table (A, J, S = 1 and so on), a name in Russian letters — by the Russian alphabet table. The two popular Russian tables differ in a few letters, so the name number on two sites may differ — there’s a breakdown with examples in the article “Why the name number differs on two sites” (in Russian).
How to test it on yourself
Take your last three big decisions and see whether you recognize the description of your number in them. If you don’t recognize it in any of them, consider the calculation a miss, not something that “will show up later”: a description that fits everyone says nothing about anyone.
Numerology is not a scientific system. Everything written here is a language for self-observation, not a prediction; every claim is worth checking against your own experience.