Sun Sign Calculator

In tropical Western astrology, your sun sign is the zodiac sign the Sun occupied at the moment you were born. For most birth dates, the month and day are enough to identify it — enter them above and the calculator returns the sign.

Births close to a sign change are the exception. The Sun crosses from one sign into the next at a precise moment that falls slightly differently each year and reads differently across time zones, so a birthday sitting on a boundary date can belong to either sign. In that case the exact birth time and place — a full chart — settle it rather than a date range.

Tropical astrology divides the year into twelve thirty-degree segments anchored to the seasons: Aries begins at the March equinox, Cancer at the June solstice, Libra at the September equinox, Capricorn at the December solstice. The Sun spends about thirty days crossing each one.

Your sun sign is the segment the Sun occupied when you were born. The Sun does not change signs at midnight, and because the calendar year and the solar year don't match exactly, the changeover drifts by a few hours from year to year. That is why published boundary dates vary by a day between sources — none of them is wrong; they are rounding a moving moment.

This calculator uses the standard tropical date ranges, which hold for the large majority of birthdays. If yours falls on or beside a boundary, treat the result as provisional and confirm it with a chart built from your exact birth time and place.