Everything is worked out in your browser and saved on this device for next time.
About the moon phase calculator
The moon goes through its phases every 29.5 days: from the new moon to the full moon and back. Pick a date — today, your birthday, a wedding day — and the calculator shows the phase, how much of the moon is lit (in percent), how many days old it is, and the date of the next full moon and the next new moon.
A table lists the coming phases — new moon, first quarter, full moon and last quarter — with the day and the time on your clock.
The phases are worked out with a well-known astronomical method (Jean Meeus), so the times are right to within a few minutes.
How to use it
- Pick a date, or press Today, Tomorrow or In a week
- Read the phase, the lit part and the age of the moon
- Check the next full moon and next new moon
- Choose how many phases to show — 12, 24 or 48
The eight phases
| Phase | What you see |
|---|---|
| 🌑 New moon | The moon is dark — it is between the Earth and the Sun |
| 🌒 Waxing crescent | A thin right-side sliver grows (northern hemisphere) |
| 🌓 First quarter | Half lit — the right half in the north |
| 🌔 Waxing gibbous | More than half lit and growing |
| 🌕 Full moon | The whole face is lit |
| 🌖 Waning gibbous | More than half lit and shrinking |
| 🌗 Last quarter | Half lit — the left half in the north |
| 🌘 Waning crescent | A thin left-side sliver, before the new moon |
In the southern hemisphere the sides are the other way round.
Full moon dates in 2027
Times are UTC; your own day can differ by one.
| Month | Full moon (UTC) |
|---|---|
| January | 22 January, 12:18 |
| February | 20 February, 23:25 |
| March | 22 March, 10:45 |
| April | 20 April, 22:28 |
| May | 20 May, 11:00 |
| June | 19 June, 00:46 |
| July | 18 July, 15:46 |
| August | 17 August, 07:30 |
| September | 15 September, 23:05 |
| October | 15 October, 13:48 |
| November | 14 November, 03:27 |
| December | 13 December, 16:10 |
The calculator on this page shows these in your time, for any year you like.
Why 29.5 days?
The moon goes around the Earth in about 27.3 days, but the Earth moves around the Sun in the meantime, so the moon needs two more days to be in the same position to the Sun. That is the synodic month: 29 days, 12 hours and 44 minutes on average.
Frequently asked questions
What is the moon phase today?
Press Today and read the result. The lit part and the age of the moon update at once.
What was the moon phase on my birthday?
Pick your date of birth. The calculator works for dates far in the past and the future.
When is the next full moon?
It is shown in the result, and the table lists the next full moons with the time.
Why does the table show a different day than my calendar?
The moon changes phase at one moment in time (shown here in your clock). Calendars in different time zones can put it on different days.
How exact is the lit part in percent?
It is a smooth estimate based on the moon's age. It can be off by a few percent.
Can I use it to plan fishing, gardening or photos?
Yes, many people do. A full moon is bright for night photos; a new moon gives the darkest sky for stars.
Good to know
- Your date is saved only in this browser
- Nothing you type is sent anywhere
Related tools
- Lunar Calendar Converter — the Chinese lunar date
- Zodiac Sign Calculator — your star sign
- Day of the Week Calculator — the weekday of any date
- Date Calculator — days between dates
- Countdown to Date — count down to a night
