Our numerology methodology

Primary system: Pythagorean 3-cycle method

For all birth-date calculations — primarily the life path number — Numology uses the Pythagorean 3-cycle method, which is the most widely used approach in Western numerology and the standard taught in books such as The Complete Book of Numerology by David A. Phillips and Numerology and the Divine Triangle by Faith Javane and Dusty Bunker.

The 3-cycle method works by reducing the month, day, and year of birth separately before adding them together. This approach preserves master numbers (11, 22, 33) that would otherwise be reduced away if you simply added all digits at once.

Step-by-step: life path number example

For someone born on February 27, 1976:

1. Month: 2 → already a single digit → 2
2. Day: 27 → 2 + 7 = 9
3. Year: 1976 → 1 + 9 + 7 + 6 = 23 → 2 + 3 = 5
4. Sum: 2 + 9 + 5 = 16 → 1 + 6 = 7
5. Result: Life Path 7 (with Karmic Debt 16, displayed as 16/7)

The intermediate value 16 is preserved because it is a karmic debt number — a number that carries additional significance in many numerological traditions.

Master numbers

Master numbers — 11, 22, and 33 — are never reduced further during any intermediate step. If a month, day, or year reduces to 11, 22, or 33, that value is carried forward as-is before the final addition.

For example, a person born on the 11th has a day value of 11 (not reduced to 2), which may affect the final life path calculation.

Karmic debt numbers

The numbers 13, 14, 16, and 19 are known as karmic debt numbers in the tradition of Hans Decoz (Numerology: Key to Your Inner Self) and Matthew Oliver Goodwin (Numerology: The Complete Guide). When one of these numbers appears in the reduction chain of your life path, destiny, or other core numbers, we display it alongside the final digit (e.g., 16/7) to indicate its presence.

Name-based numbers: Pythagorean system

For destiny, soul urge, expression, and personality numbers — which are derived from your birth name — the default system is Pythagorean. In this system, the letters A–Z are assigned values 1–9 in sequence:

• Destiny / Expression: all letters in your full birth name
• Soul urge / Heart's desire: vowels only (A, E, I, O, U, and Y in most traditions)
• Personality: consonants only

Chaldean system

The Chaldean system — originating in ancient Babylon — uses a different letter-to-number mapping. Notably, the number 9 is considered sacred and is not assigned to any letter. Numology supports the Chaldean system as an alternative for name-based calculations; you can switch between systems using the toggle on any name-based calculator.

The Chaldean chart:

Personal year, month, and day

Personal year is calculated by reducing your birth month and day along with the current calendar year (not your birth year). The calculation follows the same 3-part reduction as the life path number.

Personal month is your personal year number plus the current calendar month, reduced to a single digit. Personal day adds the calendar day to the personal month.

Compatibility

Compatibility scores are based on the relationship between two life path numbers. We use a compatibility matrix derived from the common traits and tension points documented across the numerological literature, weighted by similarity, complementarity, and known harmonics. Compatibility analysis is offered as a reflective tool — not a prediction of relationship outcomes.

A note on variation across traditions

Numerology has no single canonical authority. Different books, schools, and practitioners disagree on specific rules — for example, whether Y is always a vowel, whether master numbers should be preserved in every step, or how to treat karmic numbers. Our choices align with the most widely adopted conventions among contemporary Western practitioners, including the methods used by seventhlifepath.com and the traditions documented by Hans Decoz.

If you notice a discrepancy between our results and another source you trust, it is likely due to a difference in system (Pythagorean vs. Chaldean), master number handling, or Y-as-vowel treatment. We document each calculation step in detail so you can verify the math yourself.