Chaldean Numerology — Definition
Chaldean numerology assigns letters to numbers based on the sound and vibrational quality of each letter rather than alphabetical order. It uses values 1 through 8 and reserves 9 for the divine, never assigning it directly. The Chaldean system places more emphasis on the name a person actually goes by — what other people call them — than on the legal birth name. It is widely used in Indian astrological numerology and is considered more interpretive but less accessible than Pythagorean.
Origin
Named after the Chaldeans of ancient Mesopotamia, who systematised earlier Babylonian number lore.
Example
A practitioner using Chaldean numerology will often ask which name a client uses daily, not just the legal one.