Zodiac Sign Finder
Your star sign, Chinese animal, birthstone and planet ages — facts, not forecasts.
Western zodiac (tropical)
- Sun’s position
- Constellation behind the Sun
Chinese zodiac
Birthstone
From the American Gem Society’s chart. Several stones for a month are alternatives, not a ranking.
Your age on other planets
| Planet (one year there) | Your age | Next birthday there |
|---|
Age = days since birth ÷ the planet’s sidereal orbital period (NASA JPL). One Earth year here is the sidereal year of 365.26 days.
About the Zodiac Sign Finder
Enter a date of birth to see the Western (tropical) zodiac sign, the Chinese zodiac animal with its element and stem-branch name, the birthstone of the month and your age on the other planets. The Western sign is worked out from the Sun’s actual position on that date, so a birthday on a “cusp” is settled by the real time the Sun changed sign that year — add the time of birth and the place’s time zone and the tool tells you which side you are on.
This is a cultural and astronomical reference: it gives the signs and how they are defined, never horoscopes, personality readings or predictions. Everything is calculated in your browser.
How to use it
- Enter the date of birth. The results appear straight away.
- If the result says cusp day, add the time of birth — the tool shows the minute the Sun entered the next sign.
- Pick the time zone of the birth place (it starts with your own). The clock of that place on that date is used, including summer time and older offsets.
- Read the Western sign, the Chinese sign (and whether a January or February birth falls before Chinese New Year), the birthstone and the planet ages. Change Planet ages: on which date? to see them on another day, and press Copy summary to keep the result.
Examples
15 August 1947 · no time · New Delhi
Leo (the Sun was in Leo from 23 Jul 1947, 22:45 to 24 Aug 1947, 05:39 IST) · Fire Pig, 丁亥 · Peridot, sardonyx, spinel · 42.08 years old on Mars on 4 Oct 2026
21 March 1990 · no time · Kolkata
Pisces or Aries — the Sun entered Aries at 02:49 IST that night. Born before 02:49: Pisces; at or after: Aries.
In New York the same date is simply Aries: there the equinox came on the afternoon of 20 March (16:19).
20 January 1990
Earth Snake (己巳): Chinese New Year 1990 was on 27 January, so the Horse year had not begun.
How the Western sign is found
The twelve tropical signs are 30° slices of the ecliptic counted from the March equinox: 0–30° is Aries, 30–60° Taurus, and so on to Pisces at 330–360°. The tool calculates the Sun’s apparent geocentric ecliptic longitude for your birth moment with astronomy-engine (based on the VSOP87 planetary theory) and reads off the slice. It finds the year’s ingress times the same way, and they agree with the published equinox and solstice times to the minute — for example the June solstice of 2024 at 20:51 UTC.
The usual date ranges printed in newspapers are averages: because the calendar year is not a whole number of days, the Sun can change sign on either of two dates. Without a time of birth, the tool checks the whole local day and reports a cusp when the change happened that day. It also names the constellation (by the International Astronomical Union’s boundaries) actually behind the Sun — usually not the sign of the same name, because the equinox has drifted westward by precession, and around early December it is Ophiuchus.
Chinese zodiac: lunar new year or Lichun
Most people count the Chinese zodiac year from Chinese New Year, which falls between 21 January and 20 February. The tool uses the Hong Kong Observatory’s Gregorian–lunar conversion tables for the years 1901–2100, so a birth on 20 January 1990 is correctly a Snake, not a Horse.
Four Pillars (BaZi) charts start the year at Lichun, the solar term when the Sun reaches 315° (3–5 February); the tool shows that convention too and says when the two differ. The year’s element and yin or yang come from its heavenly stem (甲乙 wood, 丙丁 fire, 戊己 earth, 庚辛 metal, 壬癸 water; the first of each pair is yang), the animal from its earthly branch — together the 60-year stem-branch name such as 丙午 for 2026.
Birthstones and planet ages
Birthstones follow the American Gem Society’s chart; where a month has several stones they are alternatives.
Planet ages use the sidereal orbital periods from NASA JPL’s Planetary Physical Parameters, given there in Julian years of 365.25 days: Mercury 0.2408467, Venus 0.61519726, Mars 1.8808476, Jupiter 11.862615, Saturn 29.447498, Uranus 84.016846, Neptune 164.79132 and the dwarf planet Pluto 247.92065. Your age on a planet = days since birth ÷ (period × 365.25), and the next birthday there is the moment that number reaches the next whole year.
Limitations
- No horoscopes, compatibility scores, personality readings or predictions — only the signs and how they are defined.
- Indian (Vedic) rashi is usually the Moon’s position in the sidereal zodiac; this tool gives the Sun’s tropical sign and does not calculate rashi, nakshatra or a birth chart.
- The Chinese New Year tables cover 1901–2100; outside those years the Chinese sign follows the Lichun convention only.
- Births are compared with Chinese New Year by the calendar date at the birth place. The Chinese calendar counts days in Beijing time, so a birth on the eve or the day of Chinese New Year in a distant time zone can fall on the other side of the new year there.
- Time zones come from your browser’s time zone database; very old local-mean-time offsets (before about 1900) can differ by some minutes from historical practice.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
Why do sites give different dates for the same sign?
The Sun enters each sign at a slightly different moment every year — up to a day earlier or later, because the calendar year is not a whole number of days and leap years reset it. Fixed tables round that off. This tool calculates the actual moment for your birth year.
I was born on a cusp. Which sign am I?
By the tropical definition you have exactly one sign: the one the Sun was in at the minute you were born. Enter your time of birth and the birth place’s time zone and the tool decides it. “Cusp sign” blends are a popular idea, not a separate sign.
Why is my Chinese animal different from what a year chart says?
Simple charts switch animals on 1 January. The Chinese year begins at Chinese New Year, between 21 January and 20 February, so January and early-February births usually belong to the previous year’s animal.
What is the 13th sign, Ophiuchus?
Ophiuchus is a constellation the Sun passes in front of every year — in 2026 from 30 November to 18 December (by the International Astronomical Union’s boundaries). The tropical zodiac has always had twelve equal signs tied to the seasons, not the constellations, so Ophiuchus does not change your sign; the tool shows the constellation separately for interest.
Is anything I enter sent to a server?
No. Your date and time of birth stay in your browser; the astronomy is calculated on your device.