Every term used across this site, defined plainly. Where a term is used differently by different practitioners, the entry says so.
Birth Number
The day of the month of birth reduced to a single digit. Governs working style and day-to-day behaviour. Someone born on the 23rd has a Birth Number of 5.
Chaldean numerology
The letter-value system that assigns values 1 to 8 by sound rather than alphabetical order. No letter carries the value 9. The primary system used for business names.
Compatibility layer
One comparison between two numbers — for example the business name against the owner's Life Path. A full reading compares several layers, and they can disagree with one another.
Compound number
The full total of a name's letter values before reduction. The more specific of the two numbers in a reading.
Consonant total
The sum of consonants only, used in Pythagorean numerology to derive the Personality number.
Destiny number
In some traditions, another term for the Expression number derived from a full name. Usage varies between sources.
Enemy planet
A planet that another planet stands in traditional opposition to. Numbers ruled by enemy planets produce friction readings.
Expression number
The Pythagorean total of every letter in a name. Describes how the name presents itself to the market.
Favourable compound
One of the nine compounds traditionally regarded as supportive in business: 19, 21, 23, 24, 25, 27, 37, 41, 51.
Friendly planet
A planet another planet supports. Numbers ruled by friendly planets amplify each other.
Jupiter (Guru)
Ruling planet of number 3. Governs knowledge, expansion, teaching and reputation.
Ketu
The south lunar node, ruling number 7. Associated with analysis, specialisation, research and detachment.
Life Path number
Every digit of the date of birth added and reduced. The owner's core number and the primary reference point for compatibility.
Lo Shu grid
A three-by-three grid showing which numbers 1 to 9 appear and which are absent. Absent numbers indicate practical gaps.
Mars (Mangal)
Ruling planet of number 9. Governs drive, competition, urgency and completion.
Master number
11, 22 or 33. Never reduced to a single digit. Carries an amplified version of base energy 2, 4 or 6.
Mercury (Budha)
Ruling planet of number 5. Governs communication, trade, speed and adaptability.
Missing number
A number 1 to 9 absent from a Lo Shu grid, read as an area the name or the person does not naturally reinforce.
Moon (Chandra)
Ruling planet of number 2. Governs relationships, trust, care and retention.
Mutual enemies
A pairing where each planet regards the other as an enemy. The strongest friction reading available.
Mutual friends
A pairing where each planet regards the other as a friend. The strongest supportive reading available.
Name correction
Adjusting the spelling of a business name so its number improves while the name stays recognisable. Usually achieved by doubling a letter, dropping a silent letter, or changing a vowel.
Neutral compound
Any compound not in the favourable, warning or master groups. Neither helps nor hinders — the majority of business names fall here.
One-sided friend
A pairing where one planet regards the other as a friend but the friendship is not returned. Common in partnership readings.
Personal Day
The Personal Month combined with the date. Used to select launch and announcement dates.
Personal Month
The Personal Year combined with the calendar month. Sets the theme for four weeks.
Personal Year
The birth day and month combined with the current calendar year. Changes every January and sets the theme for twelve months.
Personality number
The Pythagorean consonant total. Describes the first impression a name creates.
Planetary friendship
The fixed Vedic system of relationships between planets — friendly, neutral or enemy — used to decide numerological compatibility.
Pythagorean numerology
The letter-value system assigning values 1 to 9 by alphabetical position. Used for how a name presents itself rather than for structural judgement.
Rahu
The north lunar node, ruling number 4. Associated with systems, technology and unconventional method.
Reduction
Adding the digits of a number repeatedly until one digit remains, stopping at 11, 22 or 33.
Ruling planet
The planet associated with a name's single digit. Determines brand colours, favourable weekday and compatibility.
Saturn (Shani)
Ruling planet of number 8. Governs structure, endurance, capital and discipline. Slow to reward, durable when it does.
Single digit
A compound number reduced to one digit. Names the ruling planet and the broad character of a name.
Soul Urge number
The Pythagorean vowel total. Describes what a name is internally driven by.
Sun (Surya)
Ruling planet of number 1. Governs authority, leadership and visible prominence.
Vedic numerology
The system mapping numbers to planets and using planetary friendships to determine compatibility. Applied on top of Chaldean letter values.
Venus (Shukra)
Ruling planet of number 6. Governs beauty, comfort, luxury and client experience.
Vowel total
The sum of vowels only, used in Pythagorean numerology to derive the Soul Urge number.
Warning compound
One of the five compounds treated as a caution in Chaldean numerology: 13, 16, 18, 26, 29. Describes recurring obstruction patterns rather than certain failure.
Where these terms are used
The calculation terms — compound number, single digit, reduction — appear in the calculation method. The compatibility terms appear in Vedic numerology and the date-of-birth reading. The compound groups are listed in full in the compound number table.
Our methodology page sets out which convention this site follows wherever the tradition is ambiguous.