Calendars & dates / Zodiac
Moon Sign Calculator
Find your Moon sign by date of birth, check possible signs without a birth time, and see the Moon's degree and phase.
Moon Sign Calculator: Finds the Moon's tropical zodiac sign and degree. With only a date, it checks the Moon at 00:00 and 23:59 in the chosen local time zone and finds any sign-change times during that day. A known birth time gives one exact position. The result also shows the Moon's phase and illumination, with a link to the full birth chart and a card containing only the possible Moon signs. Runs 100% locally in your browser with zero server file uploads.
- Category
- Astrology & fortune
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
A birth date is enough to check the possible Moon signs. Time and place are optional; choose a city for its historical time zone, or use your browser’s zone.
Traditional Moon sign meanings
In astrological tradition, the Moon sign is associated with emotions and comfort. These keywords describe cultural symbolism, not measured personality traits.
- Aries
- Initiative and directness.
- Taurus
- Steadiness and sensory comfort.
- Gemini
- Curiosity and conversation.
- Cancer
- Care and belonging.
- Leo
- Warmth and expression.
- Virgo
- Practical care and attention.
- Libra
- Harmony and companionship.
- Scorpio
- Depth and emotional privacy.
- Sagittarius
- Freedom and exploration.
- Capricorn
- Structure and responsibility.
- Aquarius
- Independence and community.
- Pisces
- Imagination and sensitivity.
Astrology is a cultural and entertainment practice; this result makes no predictions.
City data: GeoNames, cities15000, filtered to population 50,000 or more plus capitals; alternate names included. Licensed under CC BY 4.0. GeoNames attribution
How the Moon sign is computed
The Moon sign is the sign containing the Moon's geocentric longitude in the tropical zodiac, measured in the true ecliptic of the chosen date. A date without a time is checked from local midnight to the next local midnight, so daylight-saving changes are included. Sign changes are located by narrowing the time interval to better than one minute. The displayed start and end degrees are for 00:00 and 23:59 local.
The phase is based on the Moon's elongation from the Sun, and illumination is the lit fraction of its disc. Without a birth time, the phase and illumination are shown for local noon. Sources: Jean Meeus, Astronomical Algorithms, second edition; astronomy-engine documentation (https://github.com/cosinekitty/astronomy) explains the MIT-licensed lunar calculations. City data from GeoNames (https://www.geonames.org/) is licensed under CC BY 4.0 and includes cities of at least 50,000 residents plus capitals.
Moon signs and the big three
In astrological tradition, the Moon sign is associated with emotions, habits and comfort. The twelve short descriptions are symbolic themes, not measurements of personality or predictions. A sign-change day can have two possible Moon signs; a recorded birth time helps choose between them.
The Sun, Moon and rising sign together are called the big three. The rising sign depends strongly on the birth time and location. Use the birth chart calculator to see all three with planetary degrees, houses and aspects.
How to use it
- Enter your birth date and add a birth time if you know it.
- Choose a city or time zone; otherwise the browser's time zone is used.
- Calculate your Moon sign, check any sign-change time and save a card.
Privacy & limitations
Your birth details and results stay in your browser. The share card never includes your date, time or place.
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Frequently asked questions
Why does the birth time matter?
The ascendant and houses depend on the Earth's rotation and can move noticeably within minutes. The Moon can also change sign during a birth date. Use the recorded local time and the historical time zone when you know them.
Which house system should I choose?
Placidus divides daily arcs and is a common default. Whole Sign gives each zodiac sign one house; Equal starts twelve 30-degree houses at the ascendant. These are different astrological conventions. Placidus falls back to Whole Sign at high latitudes.
How accurate are the positions?
An astronomy library computes the positions at about arcminute level for ordinary modern birth dates. Planet longitudes are checked against independent reference charts from 1950 to 2023. A rounded birth time or an incorrect historical UTC offset can introduce much larger differences, especially for the ascendant.
What are the big three?
The big three are the Sun sign, Moon sign and rising sign. Astrological tradition associates them with expression, emotional comfort and outward presentation. They are cultural interpretations and make no predictions.
What if I do not know my birth time?
The birth chart's time-unknown option uses local noon and hides the ascendant, Midheaven and houses. The Moon calculator checks the whole local date and shows any sign changes with their local times. Two possible Moon signs need a birth time to distinguish them.
Are my birth details private?
All calculations and image exports happen in your browser. Your date, time and place are not uploaded or included on the share card.
Free tool · runs in your browser · no account required