Moon Phase Calculator
Choose a date and time to see the phase, the share of the moon that is lit and when the next new moon, first quarter, full moon and last quarter arrive.
Times are shown in the time zone of your device. The picture shows the moon as seen from the northern hemisphere.
Worked examples
New moon
April 2024
8 April 2024, 18:21 UTC
The date of a total solar eclipse.
Full moon
April 2024
23 April 2024, 23:49 UTC
In the UK this was after midnight, on 24 April.
Last quarter
April 2024
1 May 2024, 11:27 UTC
Half lit and waning.
About Moon Phase Calculator
The moon takes about 29.5 days to go from one new moon to the next. In that time the lit part we see grows from a thin crescent to a half moon at first quarter, then to a full disc at full moon, and shrinks again through last quarter back to new. Choose a date and time and this calculator names the phase, shows a picture, gives the share of the moon that is lit and the moon's age in days since the last new moon.
The dates of the four main phases are worked out from published astronomical formulas that agree with almanac tables to within a few minutes, which is much better than a simple 29.5 day cycle that can be half a day out. You get a table of the next four phases and a list of every phase in the month you chose, with times in the time zone of your device. The picture shows the moon as seen from the northern hemisphere; in the southern hemisphere the lit side is the opposite one.
How to use Moon Phase Calculator
- Choose a date and, if you like, a time.
- Read the phase, the percentage lit and the age of the moon.
- Check the table for the next new moon, first quarter, full moon and last quarter.
- Scroll to the month list to plan around a specific phase.
Common uses
- Planning night photography or stargazing
- Choosing a night for fishing, sailing or a walk
- Checking the moon on a birthday or event date
- Gardening by the moon
Frequently asked questions
When is the next full moon?
The table under the picture shows the next full moon with its date and time in your time zone.
How accurate are the times?
Within a few minutes of almanac values. For the full moon of 23 April 2024 the result is 23:49 UTC, the same as published tables.
What does the percentage lit mean?
It is the share of the visible disc that is lit by the sun. It is 0 at new moon, 50 at the quarters and 100 at full moon.
Why is the moon sometimes seen in the daytime?
The moon rises about 50 minutes later each day. A first quarter moon rises around midday and is easy to see in the afternoon.
Does the phase depend on where I am?
No. The phase is the same everywhere. Only the time of day shown depends on your time zone, and the tilt of the picture depends on your hemisphere.