instrument
Numerology
Pythagorean and Chaldean run on the same name, so you can watch them disagree.
Numerology converts the letters of a name into numbers and reads the result. There are two systems in common use in the English-speaking world, they assign different values to the same letters, and almost nobody is shown both at once.
This instrument runs them side by side. Type a name and you will usually get two different answers, from two systems that both claim to be describing you.
That disagreement is the point. It is not a flaw in one of them that the other has fixed — the two have separate lineages, separate justifications, and no agreed method for deciding between them. Where they differ, both readings are shown, and neither is marked correct.
Three of the four numbers come from the letters, so they change between systems. The Life Path does not — it is calculated from the birth date, uses no letters at all, and so comes out the same either way. That is worth noticing: the one figure the two systems agree on is the one neither of them had any say in.
The two switches under the form are there because practitioners genuinely disagree about them. Whether Y counts as a vowel changes the Soul Urge and Personality numbers. Whether master numbers are left unreduced changes several. Move them and watch the answer move.
What this does not do
It does not tell you anything about yourself. It shows you what a documented tradition says about a symbol, and it shows you a second tradition saying something else about the same symbol.
The history is in the Library: the modern system is American and datable, the attribution to Pythagoras does not hold up, and the older practice these descend from is gematria, which works on the Hebrew alphabet and is a different thing done for different reasons.