How to Use This Glossary
This glossary defines the technical terms of the Pythagorean system in thematic order: first the base mathematical concepts, then the static numbers, the temporal cycles, and finally the comparative methodology terms. Each entry includes the definition and, where applicable, the calculation formula.
Base Mathematical Concepts
Arithmetic reduction (digit reduction)
The central process of the Pythagorean system. It consists of summing the digits of a number repeatedly until a single-digit value (1–9) or a master number (11, 22, 33) is obtained.
Process:
- Non-master two-digit number: 25 → 2+5 = 7
- Two-digit master number: 11, 22, 33 → preserved as-is
- Larger number reducing to master: 47 → 4+7 = 11 → master number, preserved
- Larger ordinary number: 64 → 6+4 = 10 → 1+0 = 1
Master number
A value that is not reduced further in the Pythagorean system when it appears as an intermediate or final sum. The only three master numbers recognized in the standard system are 11, 22, and 33.
Any other multi-digit sum (44, 55, 66, etc.) is not a master number in the standard Pythagorean system and is reduced normally.
Pythagorean letter-to-number table
The assignment table that converts alphabet letters into numerical values from 1 to 9. Letters are assigned sequentially: A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8, I=9, J=1 (restarts), K=2, etc.
Isopsephy / Gematria
Ancient techniques for assigning numerical values to letters. Isopsephy is the Greek version; gematria is the Hebrew version. The modern Pythagorean system takes its name and philosophy from Pythagoras but applies a different, sequential 1-to-9 assignment table.
The Five Static Numbers
Life Path
The most studied number in the system. Obtained by summing all digits of the complete birth date (day, month, and four-digit year) and reducing the total.
Formula: reduction of (D1+D2 + M1+M2 + Y1+Y2+Y3+Y4)
Source: complete birth date
Describes: fundamental behavioral tendencies, natural approach to challenges, most sustainable work style.
Possible values: 1–9, 11, 22, 33 (12 archetypes total)
Expression Number
Obtained by converting all letters of the full birth name to their Pythagorean values and summing the total.
Source: first name(s) and surnames from the birth certificate
Describes: natural communication skills, relational style, impression in professional environments.
Possible values: 1–9, 11, 22, 33
Soul Urge (Heart's Desire)
Obtained by summing the values of the vowels (A, E, I, O, U) of the full birth name.
Source: vowels of the full birth name
Describes: internal motivations, private needs, the direction a person follows when there are no external pressures.
Possible values: 1–9, 11, 22, 33
Personality Number
Obtained by summing the values of the consonants of the full birth name.
Source: consonants of the full birth name
Describes: the initial impression a person projects before being known in depth. The external interface of the profile.
Possible values: 1–9, 11, 22, 33
Mathematical relationship: Expression total = Soul Urge + Personality (before reductions)
Goals Number (Birthday Number)
Obtained by summing only the digits of the birth day (not the month or year).
Source: birth day
Describes: specific aptitudes and areas where learning is particularly efficient.
Possible values: 1–9, 11 (day 29 → 11), 22 (day 22)
Note: some systems call this the "Birthday Number" or "Day Number."
The Four Temporal Cycles
Personal Year
Annual cycle. Changes each January 1st (standard convention).
Formula: reduction of (birth day + birth month + digits of current year)
Describes: the type of activity, focus, and rhythm that the current year favors for that person. Cycle from 1 to 9.
2026 example: born on May 3rd → 0+3+0+5+2+0+2+6 = 18 → 1+8 = 9
Personal Month
Monthly cycle within the Personal Year. Renews on the first day of each calendar month.
Formula: reduction of (Personal Year + current calendar month number)
Describes: the specific nuance of that month within the annual cycle. Provides monthly granularity to the Personal Year.
Example: Personal Year 6, month of March (3) → 6+3 = 9 → Personal Month: 9
52-Day Cycle
The calendar year is divided into 7 periods of 52 days (7 × 52 = 364, with a 1-day adjustment). Each period receives the corresponding cycle number (1 to 7, always 7 cycles per year).
Source: position of the current day in the year (calculated from the birth date and current year)
Describes: a temporal layer more granular than the Personal Year, suitable for planning projects spanning weeks or months.
Important: the system always has exactly 7 cycles per year, never more or fewer. The total number of cycles is fixed.
Daily Number
The highest-resolution temporal indicator in the system. Changes every day.
Formula: reduction of (Personal Year + day number of the month)
Describes: the nuance of the day within the Personal Month. The most detailed planning tool in the system.
Example: Personal Year 6, day 14 of the month → 1+4 = 5 → 6+5 = 11 → Daily Number: 11
Comparative Methodology Terms
Pythagorean System vs. Chaldean System
The Pythagorean system uses a sequential assignment table from 1 to 9 (A=1, B=2… I=9, J=1…) and includes master numbers 11, 22, and 33. It is the standard system in Europe and the Americas.
The Chaldean system uses values from 1 to 8 with a non-sequential assignment table and does not include master numbers. It is the predominant system in some South Asian traditions.
This platform uses the Pythagorean system exclusively.
Birth name vs. use name
The Pythagorean system distinguishes between the birth name (first name and surnames from the birth certificate) and the use name (everyday name, nickname, or stage name). The static profile numbers are always calculated from the birth name. Use names produce different values that some systems analyze as a complement, not the primary profile.
Numerological archetype
The set of behavioral tendencies, work preferences, and documented characteristics for each number from 1 to 9 and the master numbers. It is not a deterministic prediction or a fixed identity, but a reference framework based on observed patterns.
Complete numerological profile
The set of nine values of the Pythagorean system: five static (Life Path, Expression, Soul Urge, Personality, Goals) plus four temporal (Personal Year, Personal Month, 52-Day Cycle, Daily Number). Each value comes from a different data source and describes a different aspect of the profile.
Calculate Your Profile
To obtain the five static numbers you need your complete birth date and your full birth name. The four temporal cycles are calculated from the static numbers plus the current date. The platform calculates all values and shows the complete arithmetic process.