Find the moon phase on any date
Find the moon phase and approximate illumination percentage for any date, past or future.
Calculated in your browser. Nothing you enter is sent to a server.
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Date
Enter a date to find the moon phase.
01
Pick a date
Defaults to today, but you can check any past or future date.
02
See the moon phase
One of the eight named phases, from New Moon to Full Moon and back.
03
Read the details
Approximate illumination percentage and the moon's age in days since the last new moon.
Frequently asked
How accurate is this?
It's based on the mean length of a synodic month, accurate to within about a day. It's precise enough for general reference, not for astronomy-grade timing.
What does 'moon age' mean?
It's the number of days since the most recent new moon, from 0 (a new moon) up to about 29.5 (the length of a full lunar cycle).
Can I check a future date?
Yes. The calculation works for any date, past or future, since it's based purely on the elapsed time from a known reference new moon.
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