Fun
Zodiac Sign Calculator
Find your Western zodiac sun sign from your birthday — and if you were born on a cusp, settle it with the Sun’s exact position.
For entertainment and cultural interest. Sun signs describe where the Sun was in the sky, not what a person is like; astrology’s claims about personality have not held up in scientific tests.
Play and explore in your browser. No account needed.
Frequently asked questions
What is a sun sign?
It is the sign of the zodiac the Sun appeared to be in when you were born. Over a year the Sun appears to travel once around the ecliptic, the band of sky the planets move through, and Western astrology divides that circle into twelve equal 30° signs, starting with Aries at the March equinox. When people ask “what’s your sign?”, they mean the sun sign.
Why do zodiac dates differ between websites?
The Sun enters each sign at a particular moment, not at midnight on a fixed date, and that moment shifts from year to year. A calendar year is about six hours longer than 365 days, so each ingress falls about six hours later every year until a leap day pulls it back, and the 400-year leap year cycle adds slower drift. Between 1950 and 2050, for example, the Sun entered Aries anywhere from March 19 to March 21 in UTC. Fixed tables round all of this to one set of dates, and different sources round differently.
What does it mean to be born on the cusp?
Informally, “on the cusp” means born within a day or two of a sign change, and some astrologers say you blend both signs. In the calculation itself there is no overlap: at any instant the Sun is in exactly one sign. If the Sun changed sign on your birthday, your sun sign depends on whether you were born before or after that moment, which is why this page asks for your birth time and time zone.
What are elements and modalities?
They are two traditional ways of grouping the twelve signs. The four elements are fire, earth, air and water, with three signs each. The three modalities, or qualities, are cardinal (the signs that start each season), fixed (mid-season) and mutable (end of season), with four signs each. Every sign has a unique combination of the two, such as Aries being cardinal fire.
What about Ophiuchus, the 13th sign?
Western astrology uses the tropical zodiac: twelve equal 30° signs measured from the March equinox. They are named after constellations but are not the constellations. Because of the slow wobble of Earth’s axis, the signs and the constellations have drifted apart by roughly 24° since antiquity, and the Sun also passes through Ophiuchus, which the zodiac never included. Vedic (sidereal) astrology uses signs tied to the stars instead, so it usually gives a different sign.
Can my zodiac sign predict my personality or future?
There is no scientific evidence that it can. Controlled studies have not found that sun signs predict personality, compatibility or life events. The traits listed on this page are traditional associations from astrology, included for fun and cultural interest. The part that is science is the calculation of where the Sun was on your birthday.
About this tool
This zodiac sign calculator finds your Western sun sign from your date of birth. For most birthdays the answer is simple, and the page shows the sign together with its symbol, element, modality and traditional ruling planet, plus the keywords astrology traditionally links to it. Unlike a fixed date table, it works the answer out from the Sun’s real position in the sky on the day you were born.
The fixed dates printed in horoscope columns are a simplification. The Sun enters each sign at a precise moment, and because the calendar year does not divide evenly into days, that moment moves by several hours from one year to the next. So someone born on March 20 might be a Pisces one year and an Aries another. The calculator finds the exact moment the Sun crossed into each sign for your birth year and shows them in a table for your time zone.
The Sun’s position is calculated with the solar theory in Jean Meeus’s Astronomical Algorithms, including nutation, aberration and the main perturbations from the Moon and planets. Checked against the US Naval Observatory’s equinox and solstice times, which are the moments the Sun enters Aries, Cancer, Libra and Capricorn, the results agree to within a minute or two for every year tested from 1901 to 2099.
The page treats astrology as what it is: a cultural tradition that many people enjoy, not a science. The sign calculation is astronomy, while the personality descriptions come from astrological tradition and are presented as such. Everything runs in your browser, and your birth date is never sent anywhere.