Astronua

Sun sign calculator

Calculate your Sun sign, its degree and decan from your birth date, time and place. For people born on a cusp day, the time and place matter.

If you don't know the time, leave 12:00; the Moon sign and rising sign depend on it.

We find the location from the district, province and country, then add the latitude, longitude and the time zone in force on that date (including daylight saving time).

Enter coordinates manually

If the place can't be found, enter the latitude, longitude and the UTC offset at the time of birth. When these are filled in, they are used instead of the place names.

Your birth date, time, place and name are stored only in this browser and are never sent to our server.

How is the Sun sign calculated?

  1. Moment of birth

    Latitude, longitude and time zone are found from the district, province and country; the birth time is converted to universal time with the UTC offset in force on that date.

  2. Sun's longitude

    The Sun's ecliptic longitude is calculated with astronomy-engine.

  3. Sign

    The longitude is divided into twelve 30° signs: 0° Aries, 30° Taurus, 60° Gemini… Western astrology uses the tropical zodiac tied to the seasons.

  4. Decan

    Each sign is divided into three 10° decans. Each decan has a sub-ruler from the same element; for example, the second decan of Aries carries the colour of Leo, the third of Sagittarius.

Sign = ⌊Sun longitude / 30°⌋
Decan = ⌊degree within sign / 10°⌋ + 1

Why do sign dates shift a little each year?

A year isn't exactly 365 days and leap years shift the calendar, so the day the Sun changes sign can move by a day from year to year. If you were born on a cusp day, this calculator gives you the exact result.

Frequently asked questions

Is the birth time needed?

The Sun moves about 1° a day. If you were born on a cusp day, the time can change the result; on other days the result is the same even without it.

Sun sign, Moon sign or rising sign?

The Sun sign describes your core personality, the Moon sign your emotions, the rising sign your appearance and first impression. Use the birth chart calculator to see all three together.

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