Moon Sign Calculator
Your Moon sign is the zodiac sign the Moon was passing through at the moment you were born. Enter your birth date, time and time zone to find it to the arc minute, even if you don't know your birth time.
Last updated:
From your birth certificate if possible
Historical daylight saving time is applied automatically for the chosen zone
Include daylight saving, e.g. −4 for New York in summer, 5.5 for India
How to use the Moon Sign Calculator
- Enter your birth date and your birth time as it was shown on the local clock.
- Choose your birth time zone. Daylight saving time in force on that date is applied for you. Born elsewhere? Pick Enter UTC offset manually.
- Don't know your birth time? Tick the box and the calculator checks the whole day instead.
- Press Calculate Moon sign to see your Moon sign, degree, Sun sign and the Moon phase you were born under.
- Read the description, check the boundary warning if one appears, and open the steps to see how the position was calculated.
How the Moon sign is calculated
Unlike your Sun sign, the Moon sign can't be read from a date chart. The Moon circles the zodiac in about 27.3 days, so it moves roughly 12° to 15° per day (faster near perigee, slower near apogee) and changes sign every two to two and a half days. This calculator works it out the way an astronomical ephemeris does:
- Universal Time. Your local birth time minus the UTC offset that applied on that date, including daylight saving time. For example, 14:30 in New York on 21 August 1995 (EDT, UTC−4) is 18:30 UT.
- Julian Day and Terrestrial Time. JD = Unix days + 2,440,587.5. A small correction ΔT (about 61 seconds in 1995) converts Universal Time to the uniform time scale the lunar theory uses.
- Fundamental arguments. With T = (JDE − 2,451,545) ÷ 36,525, the Moon's mean longitude L′, mean elongation D, the Sun's anomaly M, the Moon's anomaly M′ and argument of latitude F are polynomials in T.
- Periodic terms. The true longitude is L′ plus the sum of 59 sine terms such as 6.288774° × sin M′ (the equation of the centre) and 1.274027° × sin(2D − M′) (the evection), plus small terms for Venus, Jupiter and the Earth's flattening.
- Nutation. Adding the nutation in longitude (up to ±17″) gives the apparent ecliptic longitude λ.
- Sign. Every 30° of λ is one sign, starting from 0° Aries at the March equinox: sign number = floor(λ ÷ 30) + 1, and the remainder is the degree within the sign.
The method is the one published by Jean Meeus in Astronomical Algorithms (2nd ed., chapter 47). Its own test case, 12 April 1992 at 0h TD, gives λ = 133.1627°, which this calculator reproduces.
Moon signs at a glance
| Moon sign | Longitude | Element | Emotional needs (traditional keywords) |
|---|---|---|---|
| ♈︎ Aries | 0° to 30° | Fire | Action, independence, a quick outlet for feelings |
| ♉︎ Taurus | 30° to 60° | Earth | Comfort, stability, physical security |
| ♊︎ Gemini | 60° to 90° | Air | Conversation, variety, mental stimulation |
| ♋︎ Cancer | 90° to 120° | Water | Home, family, being cared for and caring |
| ♌︎ Leo | 120° to 150° | Fire | Appreciation, play, loyalty |
| ♍︎ Virgo | 150° to 180° | Earth | Order, usefulness, practical care |
| ♎︎ Libra | 180° to 210° | Air | Harmony, partnership, fairness |
| ♏︎ Scorpio | 210° to 240° | Water | Depth, trust, emotional honesty |
| ♐︎ Sagittarius | 240° to 270° | Fire | Freedom, optimism, adventure |
| ♑︎ Capricorn | 270° to 300° | Earth | Structure, goals, self-reliance |
| ♒︎ Aquarius | 300° to 330° | Air | Friendship, independence, ideals |
| ♓︎ Pisces | 330° to 360° | Water | Quiet, imagination, compassion |
Tips for an accurate result
- Use the recorded birth time. Family memories are often rounded to the hour. The Moon moves about 0.5° per hour, so an error of an hour or two only matters when your Moon is within a degree or so of a sign boundary; the calculator warns you when that is the case.
- Pick the zone, not just the offset. Choosing a named zone lets your browser's time zone database apply historical daylight saving rules (for example the US year-round DST of 1974 or UK double summer time in the 1940s). Use the manual offset only if your birthplace isn't covered.
- Births near midnight. If you were born close to midnight, double-check the date on the certificate: a birth at 00:10 belongs to the new day.
- Sun, Moon and rising. The "big three" of a birth chart are the Sun sign, Moon sign and ascendant. The ascendant also needs your birth place, so use the rising sign calculator for that one.
Frequently asked questions
What is a Moon sign?
Your Moon sign is the zodiac sign the Moon occupied, measured along the ecliptic, at the moment you were born. Western astrology links it with your emotional nature, instincts and what makes you feel secure, while the Sun sign describes your core identity.
Why is a Moon sign calculator needed when a Sun sign is just a date range?
The Sun spends about a month in each sign, so a calendar table works. The Moon moves about 13° a day and passes through a sign in roughly 2 to 2.5 days, so its sign depends on the exact year, date and often the hour of birth. It has to be calculated from an ephemeris.
Can I find my Moon sign without my birth time?
Often, yes. The calculator checks the Moon's position from midnight to midnight on your birth date. On a little more than half of all days (the Moon covers about 13° of a 30° sign per day) the Moon stays in one sign the whole day, so the result is certain. If it changed signs that day, you will see both possible signs and the local time it crossed over.
How accurate is this Moon sign calculator?
It uses the lunar theory from Jean Meeus's Astronomical Algorithms (chapter 47, 59 periodic terms plus corrections for Venus, Jupiter and Earth's flattening), with ΔT and nutation. That is accurate to roughly 0.003° (about 10 arcseconds), which is far finer than any birth time is recorded.
Why does the time zone matter?
The calculation needs Universal Time. A birth at 11 pm in New York is already the next day in UTC, and the Moon moves about half a degree per hour, so a wrong offset or a missed daylight saving hour can shift the degree and, near a sign boundary, the sign itself.
Which zodiac does this use, tropical or sidereal?
It uses the tropical zodiac, where 0° Aries is the March equinox point, as in Western astrology. Vedic (sidereal) astrology measures from the stars and is currently about 24° behind, so a sidereal Moon sign is often one sign earlier.
Is astrology scientific?
No. The Moon's position is real astronomy and is calculated precisely here, but the personality meanings linked to Moon signs are a cultural tradition, not science. Use the descriptions for fun and reflection.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.