Rising Sign Calculator

Your Rising sign — the ascendant — is the sign that was coming up over the eastern horizon when you took your first breath. It is your surface and your style: the first impression you make, the way you start things, and the lens through which the rest of your chart is expressed. Of the Big Three, it is the one most sensitive to the details, which is why this calculator asks for time and place.

Birth date

Birth time

Timezone (UTC offset at birth)

Birth city (fills coordinates)

Latitude (−90…90)

Longitude (−180…180)

The ascendant changes sign roughly every two hours, so an accurate birth time matters. Use the UTC offset that was in effect where and when you were born (including daylight saving, if it applied) — our city presets use standard time, so adjust the offset if you were born during daylight saving. Results near a sign boundary (within ~1°) can shift with small time corrections.

About accuracy

The ascendant moves one degree roughly every four minutes, so a birth time rounded to the nearest half hour is usually enough — but if your result lands within a degree of a sign boundary, a corrected birth time can change it. Timezones are the classic trap: you must use the UTC offset that applied at your birthplace on your birth date, including daylight saving if it was in force. Our city presets load standard-time offsets; if you were born during daylight saving, adjust the offset by one hour.

How we calculate it

We compute Greenwich apparent sidereal time for your birth moment (via astronomy-engine), rotate it by your birthplace longitude to get local sidereal time, and solve for the ecliptic degree crossing the eastern horizon at your latitude. The formula was verified against the geometric sunrise test: at the moment the Sun's centre crosses the horizon, the calculated ascendant equals the Sun's longitude to within a few thousandths of a degree.