Moon sign calculator
Your Sun sign comes from your birthday. Your Moon sign doesn’t: the Moon crosses a whole sign in about two and a half days, so you need the day, and often the hour, to know where it was.
- Moon sign & degreeThe sign the Moon was in at your birth, to the minute of arc.
- Sign-change warningIf the Moon changed sign on your birthday and the time is unknown, we tell you rather than pick one.
- Moon’s houseWith a birth time: the house of the chart the Moon falls in.
- The rest of the chartSun, Rising, every planet and aspect come with it.
How it’s calculated
The Moon moves about 13° a day, faster than anything else in the chart. A birth time that’s six hours off moves it by three degrees, which matters whenever it sat near the edge of a sign.
We convert your local birth time to UTC with the IANA time-zone history of your birth city (old daylight-saving rules included), then compute the Moon’s apparent position with our own ephemeris, tested against Swiss Ephemeris.
If you don’t know the time, we calculate for noon and check the whole day. When the Moon stays in one sign from midnight to midnight, the sign is certain. When it crosses into the next sign that day, the chart says the Moon sign is uncertain.
Asked often
What does the Moon sign mean in astrology?
Astrologers read the Moon as the emotional side of a chart: what helps you feel safe, how you react before you think, what you need from the people close to you. The Sun is often described as who you’re becoming; the Moon as what you come home to.
Can I find my Moon sign without a birth time?
Usually, yes. The Moon spends about two and a half days in each sign, so on most dates it doesn’t change sign at all. If it did change sign on your birthday, the calculator says so and you’ll need the time to know which one it is.
Why do other websites give me a different Moon sign?
Most often it’s the time zone. Some calculators ignore historical daylight-saving time or use a modern offset for an old date, which can shift the Moon by half a degree or more. We use the IANA zone history of your birth city. If the Moon was within a degree of a sign boundary, small differences in the birth time decide it.
Is the Moon sign the same as the Moon phase?
No. The phase is the angle between the Sun and Moon (new, full, waxing, waning). The sign is where the Moon stood in the zodiac. A full Moon can fall in any sign.
How is the Moon sign different from the Rising sign?
The Moon sign is the Moon’s position; the Rising sign is the zodiac sign on the eastern horizon at your birth. The Rising sign needs an exact birth time; the Moon sign often doesn’t.
Your Moon, in a chapter
The natal chart book gives the Moon a chapter of its own, read with the rest of your chart. The love reading looks at the Moon together with Venus and the 7th house.