To calculate your zodiac sign today, you need to know your date of birth and the current position of the sun in the zodiac. The sun moves through each of the 12 zodiac signs every year, spending about a month in each one. The date when the sun changes signs varies slightly from year to year, so you need to check an online horoscope or an ephemeris (a table of celestial positions) to find out the exact date and time of your sun sign change.
Once you know your sun sign, you can read your daily horoscope from various sources, such as Astrology.com, USA Today or Astroyogi.com. These websites provide free daily and monthly horoscopes for each zodiac sign, based on the general trends and influences of the planets and stars. They also offer advice on love, finance, health and career, as well as insights into your personality and compatibility with other signs.
However, keep in mind that your zodiac sign today is only one part of your astrological profile. There are many other factors that affect your horoscope, such as your moon sign, rising sign, planetary aspects and transits. To get a more accurate and personalized reading, you may want to consult a professional astrologer or use a natal chart calculator online.