Find your zodiac sign — exactly, even on a cusp
This zodiac sign calculator tells you your Western Sun sign from your birth date, together with its element, modality, ruling planet, symbol and opposite sign, and draws the sign’s star pattern while you watch. Most sign finders use a fixed table of dates, but the Sun does not change sign on the same day every year: depending on the year, Aries can begin on 19, 20 or 21 March. Here the Sun’s actual position is calculated for your birth moment, so people born on a cusp get a definite answer.
It is meant for fun — birthday cards, curiosity, or settling whether you are “really” a Virgo or a Libra. Astrology is a cultural tradition, not a science, and nothing on this page claims your sign predicts anything about you.
Everything is calculated in your browser; your birth date is not sent anywhere.
How to use the Zodiac Sign Calculator
- Enter your Birth date. The sign, its symbol and its details update straight away.
- If you were born within a day or two of a sign change, add your Birth time and choose the Time zone at birth (the zone of the place you were born, which is preset to your device’s zone for that date).
- Read the cusp note: it says when the Sun changed sign that year and which side of the change you fall on.
- Look at the star pattern, the traditional keywords and the date table, where the Sun’s exact entry date into every sign is shown for your birth year.
Zodiac Sign Calculator features
Exact cusp answers
The Sun’s apparent ecliptic longitude is computed with the low-precision solar formulas from Jean Meeus’ Astronomical Algorithms (accurate to about 0.01°, roughly a quarter of an hour of time), so the sign change is placed to the minute for any year from 1800 to 2200.
Element, modality and rulers
Fire, earth, air or water; cardinal, fixed or mutable; the traditional ruling planet plus the modern ruler for Scorpio, Aquarius and Pisces.
Sidereal sign too
Vedic (Indian) astrology uses the sidereal zodiac, which is about 24° behind the tropical one today. The calculator shows that sign as well, using the Lahiri ayanamsa.
Animated star pattern
Stars pop in and the figure is traced line by line in a small night-sky panel; the animation is skipped if your device asks for reduced motion.
Year-specific date table
All twelve signs with their usual dates and the exact moment the Sun entered each one in your birth year, in your chosen time zone.
Zodiac signs, dates, elements and rulers
The dates below are the usual ranges printed in horoscopes. In any given year the start of each sign can move by a day either way, because a calendar year is not exactly 365 days and leap years reset the drift.
| Sign | Usual dates | Element | Modality | Ruler |
|---|---|---|---|---|
| Aries (ram) | Mar 21 – Apr 19 | Fire | Cardinal | Mars |
| Taurus (bull) | Apr 20 – May 20 | Earth | Fixed | Venus |
| Gemini (twins) | May 21 – Jun 20 | Air | Mutable | Mercury |
| Cancer (crab) | Jun 21 – Jul 22 | Water | Cardinal | Moon |
| Leo (lion) | Jul 23 – Aug 22 | Fire | Fixed | Sun |
| Virgo (maiden) | Aug 23 – Sep 22 | Earth | Mutable | Mercury |
| Libra (scales) | Sep 23 – Oct 22 | Air | Cardinal | Venus |
| Scorpio (scorpion) | Oct 23 – Nov 21 | Water | Fixed | Mars (modern: Pluto) |
| Sagittarius (archer) | Nov 22 – Dec 21 | Fire | Mutable | Jupiter |
| Capricorn (sea-goat) | Dec 22 – Jan 19 | Earth | Cardinal | Saturn |
| Aquarius (water-bearer) | Jan 20 – Feb 18 | Air | Fixed | Saturn (modern: Uranus) |
| Pisces (fish) | Feb 19 – Mar 20 | Water | Mutable | Jupiter (modern: Neptune) |
How the calculator decides your sign
In Western (tropical) astrology your Sun sign is simply the 30° slice of the ecliptic the Sun occupied when you were born, counted from the March equinox: 0–30° is Aries, 30–60° Taurus and so on. The calculator converts your birth date and time to Universal Time, adds the small ΔT correction between clock time and astronomical time, and evaluates the Sun’s mean longitude, equation of centre, nutation and aberration. Dividing the longitude by 30 gives the sign.
To find cusp times it solves for the moment the longitude crosses the next multiple of 30°. As a check, the March 2000 equinox comes out at about 07:35 UTC on 20 March, matching almanacs. Without a birth time the calculator assumes noon and warns you when the sign changed during your birthday.
The sidereal sign subtracts the ayanamsa — the accumulated precession of the equinoxes, about 23.85° in 2000 and growing by 50.3″ a year. Vedic astrology gives more weight to the Moon sign (rashi), which this tool does not calculate.
Signs are not constellations
The signs were named after the constellations the Sun passed through about 2,000 years ago. Precession has since shifted them by almost a whole sign, so on your birthday the Sun probably stood in front of the constellation before your sign. The Sun also crosses a thirteenth constellation, Ophiuchus. The star figures shown here are stylised drawings, not star maps — for a real sky view try the star chart.
Zodiac Sign Calculator FAQ
What is my zodiac sign if I was born on a cusp?
You have one Sun sign — the one the Sun was in at the moment you were born. Enter your birth time and time zone and the zodiac sign calculator gives the exact answer and the time the Sun changed sign that year. “Cusp sign” is a popular idea, not a separate sign.
Why do websites disagree about the dates of my sign?
Because the Sun’s entry date varies from year to year by up to a day or two, and different sites round differently. A calculation for your actual birth year removes the guesswork.
What is the difference between Western and Vedic signs?
Western astrology uses the tropical zodiac, tied to the seasons. Vedic astrology uses the sidereal zodiac, tied to the stars, which is now about 24° behind, so most people’s sidereal sign is the previous one. Both are shown.
Does the time zone matter?
Only near a sign change. The Sun moves about 1° a day, so a few hours matter only within a day of a cusp.
Is astrology scientific?
No. Controlled studies have not found that Sun signs predict personality or events. The tool reports where the Sun was, which is astronomy, and the traditional associations, which are folklore. Enjoy them as such.
Where can I find my Chinese zodiac or birthstone?
Use the Chinese zodiac calculator, which uses real Lunar New Year dates, and the birthstone finder. The age calculator shows your exact age.