Rising Sign Calculator (Ascendant, Midheaven, Sun & Moon Sign)
Find your rising sign (ascendant) from your birth date, exact birth time, time zone and birthplace coordinates, computed astronomically from sidereal time — plus your midheaven, Sun and Moon signs and when each of the 12 signs rises.
How it works
UT = local time − offset → Julian Day · RAMC = local sidereal time in degrees = GMST + east longitude · Ascendant λ = atan2(cos RAMC, −(sin RAMC · cos ε + tan φ · sin ε)) · MC = atan2(sin RAMC, cos RAMC · cos ε) · ε = obliquity of the ecliptic (≈ 23.44°), φ = latitude; sign = ⌊λ ÷ 30°⌋
In Western astrology the rising sign (ascendant) is the zodiac sign on the eastern horizon at the moment of birth. Unlike the Sun sign it changes about every two hours, so it needs an accurate birth time, time zone and place. This calculator computes it the way astronomy software does: the local sidereal time gives which part of the sky is on the meridian, and spherical trigonometry with the tilt of Earth's axis gives the point of the ecliptic rising in the east. The astronomy is exact (it matches professional chart software to a few arc-minutes); the personality meanings astrologers attach to the result are entertainment — controlled studies have found no link between rising signs and personality.
Worked example
Born May 15, 1990 at 10:00 a.m. in Mexico City (19.43° N, 99.13° W, UTC−6): that is 16:00 UT and local sidereal time 00:55:57. The ascendant is at 110.46° of ecliptic longitude, 20°28′ Cancer — a Cancer rising, a cardinal water sign — with the midheaven at 15°11′ Aries, the Sun in Taurus and the Moon in Capricorn. On that day Cancer rose from 08:30 to 10:43 local time.
Sources: Meeus, Astronomical Algorithms (2nd ed.), ch. 12–13 · Carlson, "A double-blind test of astrology", Nature 318 (1985)
Frequently asked questions
Why do I need my exact birth time?
The ascendant moves through all 12 signs in 24 hours, about one sign every 2 hours (faster for some signs, slower for others). A birth time off by 30 minutes can change the rising sign if you were born near a boundary — check the table to see how close you are.
What UTC offset should I enter?
The offset in force at your birthplace on your birth date, including daylight saving time if it applied (e.g. New York in July = −4, Madrid in summer = +2, Mexico City before 2022 summers = −5). Historical time zones changed often, so check a time-zone history if unsure.
Is the rising sign scientifically valid?
The ascendant is a real astronomical point. The claim that it shapes personality is not supported by evidence: large studies, including Shawn Carlson's double-blind test published in Nature (1985), found astrologers could not match charts to personalities better than chance.
Why does my result differ slightly from another site?
Different sites may use a different house system for the midheaven, a sidereal (Vedic) zodiac, or a different time-zone history. This calculator uses the tropical zodiac used in Western astrology; a Vedic (sidereal) ascendant is about 24° earlier.
Related calculators
For entertainment and cultural interest only. Astrology and numerology have no scientifically demonstrated power to describe personality or predict events.