Rising sign calculator
The rising sign (Ascendant, ASC) is the sign rising on the eastern horizon at the moment of birth. Because Earth turns once on its axis every 24 hours, the entire zodiac passes over the horizon in a single day; each sign rises for about two hours on average, which is why people born on the same day can have different rising signs. The Ascendant degree is the starting point of the 1st house and is considered the most personal point in the chart. In astrology, the Ascendant describes how a person comes across to the world, their first impression, how they approach new situations and their physical appearance. Many astrologers take the ruling planet of the rising sign to be the ruler of the chart.
To calculate the rising sign, you need the time and place of birth. The Ascendant degree advances by about one degree every four minutes on average; so even a fifteen-minute error in the birth time can shift the Ascendant by several degrees, and for births close to a sign change it can change the sign itself. If the time is unknown, the Sun and planet signs can still be calculated, but the Ascendant, the houses and the exact degree of the Moon will not be reliable. In that case astrologers try to narrow down the likely time using a method based on life events called birth time rectification.
