--- title: "Our Method: Calculations and Sources" description: "How Unified Reading calculates your numbers, tropical zodiac, whole sign houses and Chinese year, with clear conventions and sources." canonical: https://unifiedreading.com/method date-published: 2026-10-26 last-updated: 2026-10-26 publisher: Unified Reading --- # Our Method: Calculations and Sources Unified Reading calculates numerology from your birth date and name, Western placements in the tropical zodiac, and your Chinese animal and element from the Lunar New Year boundary. It uses whole sign houses when birth time and place are known. Your selected life stage shapes the interpretation, while the calculations stay the same. [Open this page](https://unifiedreading.com/method) By the Unified Reading team ## What is calculated, and what is interpreted The numbers, calendar boundaries and astronomical positions are reproducible outputs. Their meanings are an interpretive layer: the Unified Reading team uses them to suggest questions, connections and practical reflections. A precise planetary longitude does not establish a personality claim. Likewise, two descriptions that seem to agree do not make an independent test of who you are. Our conventions are set out below so that a difference between calculators can be investigated. Start with the input, then the timezone, zodiac, house system and number-reduction rule. Only after those match is it useful to compare the written interpretation. ## Western astrology: tropical positions and whole sign houses We use tropical ecliptic longitude: Aries starts at the March equinox point and the zodiac is divided into twelve equal 30-degree signs. Astrodienst’s Swiss Ephemeris documentation explains the tropical reference point. Our full chart computes geocentric positions with Astronomy Engine; a decan is the first, second or third 10-degree portion of a sign. For a known birth time and place, the sign containing the Ascendant becomes the whole first house, the next sign becomes the second, and so on. This is the whole sign method described in Astrodienst’s Tables of Houses. The exact Ascendant degree still matters as a calculated angle, but it does not move the house boundary away from the start of its sign. The full chart’s astronomical positions are checked against independent Swiss Ephemeris fixtures. Those checks concern calculated longitudes, angles and house assignments; they do not validate the meanings attached to them. Astronomy Engine documents its own astronomical models and validation separately. ## Birth time, place and uncertainty A recorded local time must be converted to a UTC instant before a chart can be calculated. We resolve the selected place to a timezone and apply the historical offset for the birth date, including daylight-saving rules. IANA’s Time Zone Database documents the historical civil-time data used by the underlying timezone facilities. A current offset is not substituted for an old birth date. The engine resolves a repeated clock time to its later occurrence and a skipped clock time using the offset after the clock change. If your record falls near a daylight-saving change, that convention matters. An approximate birth time also remains approximate even when the output displays a precise number. Without a known time and resolved place, we do not supply a definite Ascendant. A solar chart uses the Sun sign as its reference and is labelled approximate. The main reading omits Moon and personal house claims when the birth time is unknown. The dedicated Moon, rising, Venus and Mars tools require a recorded time and selected place. ## Life Path, birthday number and Personal Year For the Life Path, reduce the numerical month, day and birth year separately. Reduction means adding a number’s digits repeatedly until one digit remains, stopping whenever 11, 22 or 33 is reached. Add the three reduced components and apply the same rule to their sum. Keeping a master number applies at each reduction step, not only at the final answer. The birthday number uses the day of the month alone, with the same reduction rule. The Personal Year uses the reduced birth month and birth day plus the reduced selected calendar year. It follows the calendar year used by the calculator. Changing that selected year changes the Personal Year calculation; it does not change the Life Path. These are the conventions implemented by Unified Reading’s Pythagorean-style number engine. We state them as our rules, rather than suggesting every numerology practice uses identical arithmetic. For example, adding every digit of a date in one pass can produce a different master-number result from reducing its components separately. Our calculators show the components so you can check the route to the answer. ## Expression, Soul Urge and Personality numbers We assign 1 to A, J and S; 2 to B, K and T; 3 to C, L and U; 4 to D, M and V; 5 to E, N and W; 6 to F, O and X; 7 to G, P and Y; 8 to H, Q and Z; and 9 to I and R. Expression adds all counted letters. Soul Urge adds A, E, I, O and U. Personality adds the remaining counted consonants. Each total uses the same master-preserving reduction. Y always counts as a consonant in our engine. We remove decomposable accent marks and explicitly map ø to o, æ to ae, œ to oe, ł to l and đ to d before counting. Case is ignored. Spaces, punctuation and characters outside the resulting A–Z chart do not add a value. We do not automatically transliterate every writing system; use a consistent Latin spelling and inspect the letters shown by the name calculator. A name containing no counted vowels has no Soul Urge result in the calculator, rather than a meaningful zero. The same principle applies to a missing consonant total. These handling choices are part of the calculation, so changing the spelling or vowel convention can change the result. ## Chinese zodiac: the calendar boundary comes first Our year animal, heavenly-stem element and yin–yang polarity use the zodiac year beginning at Lunar New Year. A birth before that date belongs to the preceding zodiac year, even when its Gregorian year has already changed. We use a stored Lunar New Year date table for 1924–2044. The Hong Kong Observatory’s Gregorian-Lunar Calendar Conversion Table provides a public calendar reference for checking the boundary of a particular year. Once the year is identified, the engine assigns its animal, stem element and polarity from the repeating cycle. The Hong Kong Observatory’s Heavenly Stems and Earthly Branches reference describes the stem–branch cycle. Our Chinese element result refers to the birth-year stem; the animal’s fixed element is a separate field. A year-animal profile is not a calculation of a complete Four Pillars chart. The supported table range matters for January and February births. Outside that range, the core engine has a heuristic fallback, which should not be read as a verified Lunar New Year date. The dedicated Chinese element calculator limits its inputs to the supported dates. ## How birthday pages describe a calendar date A birthday page describes a month and day shared by many birth years. Its solar degree range, sign and decan possibilities are computed across 1930–2030, using a worldwide civil-date window from midnight in UTC+14 through the end of that date in UTC−12. This is a range across possible birthdays, not a measurement of your own Sun. The page lists sign and decan possibilities and marks a cusp when the computed sign changes within that scan. Our ruler convention means the traditional ruler of the computed tropical Sun sign. Our mapping uses Mars for Aries and Scorpio, Venus for Taurus and Libra, Mercury for Gemini and Virgo, the Moon for Cancer, the Sun for Leo, Jupiter for Sagittarius and Pisces, and Saturn for Capricorn and Aquarius. Where the solar scan allows two signs, their rulers must remain distinguishable. A weekday ruler would require a birth year, so it is not inferred from the month and day alone. The birthday number is fixed by the day. The Life Path range is calculated across birth years 1930–2025, with selected years shown as checkable examples. A calendar-date page therefore cannot supply one Life Path or one personal natal chart for everyone born that day. ## What your life stage changes Life stage is the context you select, such as exploring life, building a career, being in a relationship, parenting or retirement. Age supplies a broad framing category, while selected stages supply topics and tone. If you select several stages, their topics are combined rather than forcing your life into one category. This context changes what the reading discusses. A reflection on responsibility might become a question about workload, shared commitments or caring for family. It does not change a number, planetary position or zodiac year. Your optional question adds context for the written synthesis; it is not used to alter the underlying arithmetic. ## Checking a result Use the individual calculators to inspect a number or placement, then follow its library link for the interpretation. For a disagreement, compare the full date, the counted name letters, the recorded time, selected place and method settings. For a Chinese year, compare the exact birthday with that year’s Lunar New Year boundary. For a birthday near a solar boundary, use a timed calculation rather than a fixed date-range label. The references below support the astronomical coordinate systems, house definition, timezone data and calendar structure. They are not endorsements of Unified Reading or evidence that a particular life outcome follows from a chart. The numerical and editorial conventions on this page document the choices made by Unified Reading. [How a combined reading works](https://unifiedreading.com/numerology-and-astrology) [Our method and sources](https://unifiedreading.com/method) ## Sources and calculation references - [Astrodienst: Swiss Ephemeris documentation and tropical zodiac](https://www.astro.com/swisseph/swisseph.htm) - [Astrodienst: Tables of Houses, whole sign method](https://www.astro.com/swisseph/sweph_ht_e.htm) - [Astronomy Engine: astronomical calculations and validation](https://github.com/cosinekitty/astronomy) - [IANA: Time Zone Database](https://www.iana.org/time-zones) - [Hong Kong Observatory: Gregorian-Lunar Calendar Conversion Table](https://www.hko.gov.hk/en/gts/time/conversion.htm) - [Hong Kong Observatory: Heavenly Stems and Earthly Branches](https://www.hko.gov.hk/en/gts/time/stemsandbranches.htm) ## Read next - [How a combined reading works](https://unifiedreading.com/numerology-and-astrology) - [All calculators](https://unifiedreading.com/calculators) - [Life Path calculator](https://unifiedreading.com/life-path-calculator) - [Name numerology calculator](https://unifiedreading.com/name-numerology-calculator) - [Personal Year calculator](https://unifiedreading.com/personal-year-calculator) - [Chinese zodiac years](https://unifiedreading.com/chinese-zodiac/years) [Start your free preview](https://unifiedreading.com/#details)