Find out the moon's age â days since the last new moon â plus its phase, illumination, and the upcoming full and new moons.
Pick any date to see the moon's age, phase, and illumination on that day (choose today for the current moon)
The moon's "age" is the number of days since the last new moon (0 to ~29.5 days). This calculator uses the standard synodic month (29.53 days) and a known new-moon epoch (January 6, 2000) to compute the moon's age for any date.
Because the calculation is anchored to a precise new-moon epoch and the standard synodic month, it works for any date between 1900 and 2100.
The moon's age is the number of days since the last new moon. Here is how moon age maps to phase (approximate).
| Moon Age | Phase | Typical Illumination |
|---|---|---|
| 0â2 days or 28â29.5 days | ð New Moon | 0â6% |
| 2â6 days | ð Waxing Crescent | 6â25% |
| 6â9 days | ð First Quarter | 25â55% |
| 9â13 days | ð Waxing Gibbous | 55â90% |
| 13â17 days | ð Full Moon | 90â100% |
| 17â20 days | ð Waning Gibbous | 90â55% |
| 20â24 days | ð Last Quarter | 55â25% |
| 24â28 days | ð Waning Crescent | 25â6% |
Moon age counts the days since the last new moon â the basis of lunar calendars.
Know when the full moon and new moon fall to plan the best nights for observing.
Many holidays and traditions follow the moon's age and phase.
See why the moon looks different each night â it's all about its age.
Explore our complete collection of age calculation tools