Moon phase calculator
What the Moon is doing tonight
The phase for today or any date you choose: how much of the Moon is lit, how many days into the cycle it is, and when the next full and new moon fall.
The next two weeks
Calculated from the average length of the lunar cycle, so phase times can be several hours out and the date of a full or new moon may differ by a day from an almanac, especially across time zones.
The eight phases
The Moon takes about 29.5 days to go from one new moon to the next. Half of it is always lit by the Sun; the phase is simply how much of that lit half is turned toward Earth.
| Phase | What you see | Roughly when it is up |
|---|---|---|
| New moon | Nothing: the lit side faces away | With the Sun, during the day |
| Waxing crescent | A thin sliver, growing | Low in the west after sunset |
| First quarter | Half lit | Afternoon and evening |
| Waxing gibbous | More than half, growing | Late afternoon into the night |
| Full moon | The whole disc | Rises around sunset, up all night |
| Waning gibbous | More than half, shrinking | Late evening to morning |
| Last quarter | Half lit, the other half | After midnight into the morning |
| Waning crescent | A thin sliver, shrinking | Low in the east before sunrise |
Waxing or waning?
In the northern hemisphere the lit side is on the right while the Moon is growing and on the left while it shrinks. South of the equator it is the other way round, because you are seeing the same Moon the other way up. The switch above flips the picture to match.
Why the phase matters for an evening outdoors
- Stargazing: the darkest skies are in the days around the new moon. A bright gibbous or full moon washes out faint stars and the Milky Way.
- Night walks and camping: a full moon in a clear sky is bright enough to cast shadows.
- Photography: a full moon rises close to sunset, opposite the Sun, so it can sit above a landscape still lit by the last daylight.
- Tides: the largest tidal ranges come around new and full moon.
The Moon tonight. The Sun every evening.
Asterfold: Sunset Planner is an iPhone app for planning an evening outdoors. Its listing describes sun paths and aiming for your viewpoints, tonight's Sunset, Stars and Sunrise ratings with plain-English reasons, and a journal.
Get Asterfold on the App StoreThe free tier includes the Studio and planning for two viewpoints; optional Plus purchases expand viewpoints and other features. Ratings are a rule-of-thumb estimate, not a guarantee, and sun positions assume a flat horizon.
Honest Little Apps publishes both Asterfold and this page. This is a separate browser tool and does not sync with the app. App details checked November 10, 2026.
On a computer? Open it on your iPhone
