The Constellation Calculator is a free online utility that tells you which constellation corresponds to your birthday.
What is a Constellation?
A constellation is a grouping of stars in the night sky that, when connected by imaginary lines, form a particular shape or represent an object.
While constellations can vary by culture and era, the International Astronomical Union (IAU) established 88 official constellations in 1930, which are widely used today.
12 Astrological Signs
In astrology, the sky is divided into 12 segments of 30° each along the ecliptic. These segments begin at the vernal equinox, marking the start of spring:
- Aries (March 21 ~ April 20)
- Taurus (April 21 ~ May 20)
- Gemini (May 21 ~ June 21)
- Cancer (June 22 ~ July 23)
- Leo (July 24 ~ August 23)
- Virgo (August 24 ~ September 23)
- Libra (September 24 ~ October 23)
- Scorpio (October 24 ~ November 23)
- Sagittarius (November 24 ~ December 22)
- Capricorn (December 23 ~ January 20)
- Aquarius (January 21 ~ February 19)
- Pisces (February 20 ~ March 20)
How to Calculate Your Constellation
Your constellation is determined by the position of the Sun in the sky on the day you were born.
Using your Gregorian (solar) birthday, find the matching sign among the 12 astrological signs above.
Example:
A person born on March 29 would be an Aries (March 21 ~ April 20).