What Moon Phase Was I Born Under?
Enter your birth date above to see exactly what the moon looked like the day you were born. The calculator shows the phase, the percentage of the moon's face that was lit, how many days into the lunar cycle it was, and how close you were to a full or new moon. Add your birth time for extra precision, since the moon changes slightly through the day. It also shows the moon on your birthday for the next few years, so you can plan a full-moon birthday.
The Eight Moon Phases
- New Moon: the moon is between Earth and the Sun, and its lit side faces away from us.
- Waxing Crescent: a thin sliver grows on the right, as seen from the Northern Hemisphere.
- First Quarter: half of the disc is lit, about a week after the new moon.
- Waxing Gibbous: more than half lit and still growing.
- Full Moon: the whole face is lit, about two weeks after the new moon.
- Waning Gibbous: the light starts shrinking from the right.
- Last Quarter: the left half is lit.
- Waning Crescent: a final sliver before the next new moon.
In the Southern Hemisphere the same phases appear mirrored, lit from the left first.
How the Calculation Works
One full cycle from new moon to new moon, called a synodic month, lasts about 29.53 days. The calculator finds the exact times of the new and full moons around your date using the lunar phase formulas from Jean Meeus's Astronomical Algorithms, accurate to within a minute or two for any date from 1900 to 2100. The moon's phase is the same everywhere on Earth at a given moment, so your birth location only matters for the local time.
Full Moon Names
Traditional North American names give each month's full moon a nickname: the Wolf Moon (January), Snow Moon (February), Worm Moon (March), Pink Moon (April), Flower Moon (May), Strawberry Moon (June), Buck Moon (July), Sturgeon Moon (August), Corn or Harvest Moon (September), Hunter's Moon (October), Beaver Moon (November) and Cold Moon (December). See tonight's moon and the next full moon on the moon phase today page.
