Birth information
Fill it in once: the birthday read-out, the BaZi chart and the benming years are computed together and update as you type.
Quick cases:
Birthday analysis
Lunar date, sexagenary year, animal, constellation, ages, solar terms and the life number.
BaZi four pillars
Year pillar switches at LiChun, month pillars at solar terms; the 23:00 day rule is chosen in the form above.
This tool only converts the calendar and counts elements; it makes no predictions or name advice. Enjoy it as a look at the sexagenary calendar and folk culture.
This year's animal
The current lunar year's stem-branch and animal (Lunar-New-Year convention).
Animal → years
Choose an animal and every matching year in 1900-2100 is listed.
Zodiac years (benming)
The birth year is filled in from the date above, but you can edit it.
Animal matching
Pick both animals and the harmony / clash verdict is immediate.
Features
- A full birthday read-out: lunar date, sexagenary year, animal, constellation, exact and nominal age, days lived, days to the next birthday, the solar term you were born in, the life-path number and the year pillar's sound element.
- Three zodiac helpers plus a yearly glance: animal back to every matching year in 1900-2100, the next five benming years with ages, pair matching by six-harmony / three-harmony / clash / harm / punishment rules, and this year's stem-branch animal at the top.
- BaZi charted by the traditional rules: year pillar on LiChun, month pillars on solar terms (five-tiger), a switchable 23:00 day boundary, hour pillar starting at 23:00; each pillar lists stem, branch, elements, hidden stems, sound element and ten-god relation.
- A five-element tally with bars and an explicit 'what is missing' list; ticking 'hour unknown' drops the hour pillar and switches the count to the six-character basis.
- Lunar and solar-term math comes from the battle-tested open-source lunar-javascript; the folk animal boundary (Lunar New Year) and the astrological one (LiChun) are both shown wherever they differ.
- Everything runs locally: your birthday only ever touches this page's memory, with no backend, no request and no localStorage, and the UI works in English / Simplified / Traditional Chinese.
How to use
- Type the Gregorian birth date at the top (add a time to chart BaZi) and the analysis, the four pillars and the benming years all appear at once - there is nothing to submit.
- Not sure about the hour? Tick 'birth hour unknown': the hour pillar is dropped and the tally switches to six characters. The quick cases (before LiChun / after 23:00 / right now) fill the form for you.
- To feel the two zi-hour conventions, flip the radio buttons in the form - for births between 23:00 and midnight the day and hour pillars react immediately.
- Every result block has a Copy-all button; wherever a convention splits (New Year, LiChun, solar terms) the row label names which one was used.
FAQ
- Does the zodiac animal switch at LiChun or at Lunar New Year?
- Folk usage (which animal you are, benming years, marriage matching) counts from the first day of the lunar year; astrological usage (the four pillars) counts from LiChun, the Start of Spring. Both are conventions, not mistakes: this page uses the New-Year boundary for the birthday read-out and the zodiac tools and the LiChun boundary for the BaZi year pillar, and says so wherever a birth near the boundary could read either way.
- Born between 23:00 and midnight - is the day pillar today or tomorrow?
- Two schools exist. One treats zi hour (23:00-01:00) as the start of a new day, so the day pillar advances at 23:00; the other keeps the day until midnight. Both are supported through the radio switch in the form above, which defaults to no day change; if unsure, chart the same birth at 23:30 with each option and compare.
- Why do Chinese ages (xu sui) differ from Western ages?
- The exact age counts Gregorian birthdays already passed. The traditional count starts at 1 at birth and adds a year at every Lunar New Year, so nominal age = current year - birth lunar year + 1. A January or February birth can be up to two years younger in exact age than the folk one - both numbers are shown here.
- How is the life-path number computed?
- Add all eight digits of the Gregorian birth date; keep adding the digits of the result until one digit remains. 11, 22 and 33 are kept as master numbers by the usual numerology convention. It belongs to Western numerology - it sits on this page only as a handy extra.
- Can BaZi results be trusted?
- What this page does is calendar arithmetic - converting a Beijing-time moment into the sexagenary four pillars and counting their elements; that part is deterministic and checkable. Inferring fortune from those pillars is folk culture with no scientific support, and this tool deliberately outputs no luck, date-picking or naming advice. Note also that times follow Beijing time (UTC+8) with no true-solar-time longitude correction.
About
Birth Tools merges the three w3ctool.com pages - birth analyzer, zodiac query and BaZi calculator - into a single screen: one birth entry at the top feeds the twelve-line birthday read-out and the full pillar detail cards with the element tally below it, while the zodiac glance, animal-to-years lookup, benming years and matching each react instantly to their own controls. Everything shares one calendar kernel (lunar-javascript), the same engine that backs our Perpetual Calendar.
All computing happens in your browser: the birthday and hour are only ever used in this page's memory - nothing is sent, nothing is stored, so the server never learns whose chart you ran. The lunar-javascript library (MIT, vendor/lunar.js?v=f8387354) carries solar-term data for 1901-2099; out-of-range inputs are refused with a clear message instead of being force-computed.
More tools on this site
Runs in your browser · folk lore only · free · English / 简体 / 繁體