How to find your sun sign
- Enter your date of birth.
- If you were born on a cusp day, tick this and add your birth time.
- Choose the time zone offset in force where you were born, including daylight saving.
- Read your sun sign, with the Sun's exact position, element, modality and ruling planet.
Enter your date of birth. For most birthdays that is all you need, because the Sun stays in each sign for about 30 days. If you were born on a day when the Sun changed signs, often called a cusp birthday, the calculator tells you the exact time of the change. Tick the birth time box and choose the UTC offset for your birthplace to get a definite answer.
What is a sun sign?
Your sun sign is the zodiac sign the Sun appeared to be in, seen from Earth, when you were born. It is the sign people usually mean when they ask “what is your sign?” and the one used for newspaper horoscopes. Western astrology divides the Sun’s yearly path, the ecliptic, into twelve 30 degree signs starting from the March equinox. Astrology is a cultural tradition enjoyed for reflection and fun. It has no scientific support as a predictor of personality or events.
Zodiac sign dates
| Sign | Typical dates | Element | Modality |
|---|---|---|---|
| Aries | March 21 to April 19 | Fire | Cardinal |
| Taurus | April 20 to May 20 | Earth | Fixed |
| Gemini | May 21 to June 20 | Air | Mutable |
| Cancer | June 21 to July 22 | Water | Cardinal |
| Leo | July 23 to August 22 | Fire | Fixed |
| Virgo | August 23 to September 22 | Earth | Mutable |
| Libra | September 23 to October 22 | Air | Cardinal |
| Scorpio | October 23 to November 21 | Water | Fixed |
| Sagittarius | November 22 to December 21 | Fire | Mutable |
| Capricorn | December 22 to January 19 | Earth | Cardinal |
| Aquarius | January 20 to February 18 | Air | Fixed |
| Pisces | February 19 to March 20 | Water | Mutable |
These dates shift by a day from year to year because the calendar year is not exactly as long as the Sun’s cycle and because of leap years. That is why lists online disagree on cusp dates, and why this calculator works out the Sun’s real position instead of using a fixed table.
How the calculation works
The calculator converts your birth date and time to Universal Time and finds the Sun’s apparent ecliptic longitude with the solar formulas in chapter 25 of Jean Meeus, Astronomical Algorithms. These are accurate to about 0.01 degree. Each sign covers 30 degrees.
λ = L0 + C − 0.00569° − 0.00478° sin Ω
sign = floor(λ ÷ 30): 0 = Aries, 1 = Taurus … 11 = Pisces
Worked example
For August 10, 1995, the Sun was at 137.6° at noon in UTC−04:00, which is 17°33′ Leo, comfortably inside the sign. A cusp example: on March 20, 1990, the Sun reached 0° Aries at about 21:10 UTC, which was 16:10 in UTC−05:00. Someone born that morning in Toronto is a Pisces, while someone born that evening is an Aries. The Swiss Ephemeris puts the same moment at 21:19 UTC, so cusp times here can differ by around ten minutes from professional software.
Elements and modalities
Each sign belongs to one of four elements, fire, earth, air and water, and one of three modalities. Cardinal signs start each season, fixed signs fall in the middle and mutable signs close it. Astrologers combine these to describe a sign’s traditional character, which the result panel summarizes in one line.
Frequently asked questions
What is my zodiac sign?
Your zodiac or sun sign depends on where the Sun was on your birthday. Enter your date of birth above. For example, anyone born on August 10 is a Leo.
What is a cusp birthday?
A birthday when the Sun moved from one sign into the next. Your sign depends on your birth time, so enter it with your UTC offset to get a definite answer.
Why do websites give different dates for each sign?
The moment the Sun changes sign moves by up to a day from year to year. Fixed date tables cannot capture that, which is why this calculator uses the Sun's real position.
Is my sun sign the same as my star sign?
Yes. Sun sign, star sign and zodiac sign all mean the sign the Sun was in at your birth in Western astrology.
Does astrology have scientific support?
No. Astrology is a cultural tradition enjoyed for fun and reflection. The Sun's position used here is real astronomy, but signs have not been shown to predict personality.