Birth Date
The date tells us roughly which sign the Moon is in, since it moves through a sign every 2 to 2.5 days. A correct date is the foundation of the calculation.
Free astrology tool
Moon Sign Calculator
Find your Moon sign from your birth date, time, and city. Your Moon sign describes your emotional world, your instincts, and what you need to feel secure. Enter your birth details below to find it instantly.
Moon sign lookup
Calculate Your Moon Sign
Use an exact birth time for best results. The Moon changes signs every 2–2.5 days, so time matters.
How it works
How the Moon Sign Is Found
The calculator finds the Moon’s ecliptic longitude at the exact moment of your birth using Jean Meeus’s low-precision lunar algorithm from Astronomical Algorithms (2nd ed., Chapter 47). Accuracy is within plus or minus 0.3 degrees for dates 1900 to 2100, which is more than enough for sign determination since each sign spans 30 degrees. Your birth details stay on your device and are never sent to a server.
Birth Time
The time pins the Moon’s exact position within that day. The Moon moves about 0.5 degrees per hour, so even an hour’s difference can matter near sign boundaries.
Birthplace
Your city determines your timezone. The timezone converts your local birth time to Universal Time, which is the standard used for all astronomical calculations.
Quick answers
Moon Sign Calculator FAQ
How do I find my Moon sign?
Enter your birth date, birth time, and birth city. The calculator looks up the correct timezone automatically and maps the Moon’s position to one of the 12 zodiac signs. Results appear instantly. No account or sign-up is needed.
Can I find my Moon sign without a birth time?
Yes. Check “I don’t know my birth time” and the calculator will use noon on your birth date. The Moon moves roughly 12 to 14 degrees per day. If it was far from a sign boundary, your result is still reliable. A notice will appear if the Moon was near a boundary and an exact time is needed for certainty. For the most accurate answer, check your birth certificate or ask a parent.
What does my Moon sign mean?
Your Moon sign describes your emotional inner world. It shows how you instinctively react, what makes you feel secure, and what you need to feel nurtured. While your Sun sign reflects your outward identity, your Moon sign reveals the private, feeling side of your personality. Together with your rising sign, these form the Big Three of your birth chart.
Is this Moon sign calculator free?
Yes. The Moon sign calculator is completely free, runs entirely in your browser, and does not store or transmit your birth data anywhere. There is no account, subscription, or paywall.
What is the difference between a Moon sign and a Sun sign?
Your Sun sign (your star sign) is set by the Sun’s position at birth and represents your core identity and life purpose. Your Moon sign is set by the Moon’s position and describes your emotional life, instincts, and deeper needs. Together with your rising sign, these three placements make up the Big Three in astrology. You can calculate all three together with our Big Three Calculator.
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