Sun, Moon & Rising sign calculator

What are Sun, Moon and Rising positions?

Your Sun, Moon and Rising sign positions — often called your "Big Three" — are calculated from your birth date, time and location using standard astronomical formulas (Jean Meeus, Astronomical Algorithms).

Your Sun sign position is determined from the date of birth using the Western tropical zodiac. Your Moon sign position is calculated from the Moon's ecliptic longitude at your birth moment. Your Rising sign (also called the Ascendant) is the zodiac sign that was rising on the eastern horizon at your exact birth time and location — computed using Local Sidereal Time, your geographic latitude and the obliquity of the ecliptic.

This tool calculates celestial positions for informational and entertainment purposes only. Zodiac sign interpretations are not scientifically validated.

All calculations run instantly in your browser — nothing you enter is sent to a server or stored.

Accuracy & limitations

Sun sign position is effectively exact, since it only depends on the date. Moon sign position is usually reliable, but the Moon changes sign roughly every two to three days, so if your birth falls close to a sign change, an imprecise birth time could shift the result. Rising sign is the most time-sensitive: the Ascendant moves through the full zodiac roughly once every 24 hours, shifting about one degree every four minutes. An unknown or slightly wrong birth time — or an unaccounted-for hour of daylight saving — can therefore change your Rising sign entirely. For the most reliable result, use the exact time from your birth certificate.

Accuracy & limitations

Sun sign results are effectively exact, since they only depend on the date. Moon sign results are usually reliable, but the Moon changes sign roughly every two to three days, so if your birth falls close to a sign change, an imprecise birth time could shift the result. Rising sign is the most sensitive of the three: the Ascendant moves through the full zodiac roughly once every 24 hours, so it shifts about one degree every four minutes. An unknown or slightly wrong birth time — or an unaccounted-for hour of daylight saving time — can therefore change your Rising sign entirely. For the most reliable Rising sign, use the exact time from your birth certificate and double-check the daylight saving toggle above.

Frequently asked questions

Is the Sun, Moon, and Rising the same as a full birth chart?

Not exactly. Your Big Three show where the Sun, Moon and Ascendant were positioned at your birth. A full birth chart maps every planet, house and aspect.

What's the difference between Sun, Moon, and Rising?

Sun position = based on your birth date. Moon position = birth date + approximate time. Rising (Ascendant) = exact birth time + location.

How accurate is this calculator?

Sun position is essentially exact. Moon position is accurate to a fraction of a degree using standard astronomical formulas. Rising position is highly time-sensitive — see the accuracy section above.

What if I don't know my exact birth time?

You'll still get an accurate Sun position. Without a time we default to noon, which gives a reasonable Moon position estimate but an unreliable Rising position — check your birth certificate for the exact time if possible.

Does this work for people born outside the US and UK?

Yes — choose "Other — enter coordinates manually" and enter your birth latitude, longitude and UTC offset. The formulas work anywhere in the world.

Is this fortune-telling or scientific?

This tool calculates astronomical positions using standard celestial mechanics formulas (Jean Meeus, Astronomical Algorithms). The zodiac sign mapping is based on the Western tropical zodiac convention. Results are provided for informational and entertainment purposes.