The three signs, in plain terms
Your Sun sign is the sign the Sun was in when you were born. It is the one most people know, and astrologers read it as your core identity: what energizes you and what you are growing into. It changes about once a month, so for most birthdays it is certain without a birth time.
Your Moon sign is where the Moon was. It describes your emotional life: what makes you feel safe, how you react under stress and what you need from the people close to you. The Moon changes sign every two to three days, so two people born a day apart can have different Moon signs.
Your rising sign, or Ascendant, is the sign that was coming up over the eastern horizon at the minute and place of your birth. It is read as your outward style: first impressions, your approach to new situations and often your physical presence. It changes about every two hours, which is why the exact birth time matters so much.
How the three work together
A common shorthand is that the Sun is who you are, the Moon is what you need and the rising sign is how you meet the world. A Leo Sun with a Cancer Moon and Virgo rising might be warm and expressive at heart, need a secure home life, and come across at first as careful and helpful. Reading the three together is usually more telling than any one of them alone.
| Changes sign about every | Needs your birth time? | |
|---|---|---|
| Sun sign | 30 days | Only on cusp days |
| Moon sign | 2.5 days | Sometimes |
| Rising sign | 2 hours | Always |
Accurate to the minute
The calculator converts your birth time to Universal Time using your birthplace's historical time zone, including daylight saving. The Sun and Moon come from the same planetary calculations tested against NASA JPL that power the astrocartography map, and the rising sign is computed for your exact latitude and longitude. If you know your time only roughly, the rising sign calculator lists which sign was rising at every hour of your birth day.
Going further
Your big three are a starting point. The full birth chart adds the other planets, houses and aspects. The Moon sign calculator also shows the Moon's phase at your birth. And your Sun, Moon and Ascendant each have lines on the world map, marking where they were rising, setting or overhead when you were born.