How to read the Moon tonight
The figure at the top is the Moon at this minute. The percentage is the part of the disc that is lit by the Sun as seen from Earth. The age counts the days since the last new moon. The distance is measured from the centre of the Earth to the centre of the Moon, and it swings between about 356,000 km and 406,700 km over a month.
The disc is drawn for the place shown above the picture. At first the site guesses a city from your time zone. Choose your own city, or share your position, and three things change: the moonrise and moonset times, the height of the Moon above your horizon, and the tilt of the lit edge, which is drawn as you would see it if you walked outside now.
The eight phases
| Phase | Angle from the Sun | When you see it |
|---|---|---|
| New moon | 0° | Not visible: it rises and sets with the Sun |
| Waxing crescent | 0° to 90° | Evening, low in the west after sunset |
| First quarter | 90° | Afternoon and evening, sets around midnight |
| Waxing gibbous | 90° to 180° | Most of the night, sets before dawn |
| Full moon | 180° | All night, rises at sunset |
| Waning gibbous | 180° to 270° | Rises in the evening, visible until morning |
| Last quarter | 270° | Rises around midnight, visible in the morning |
| Waning crescent | 270° to 360° | Before dawn, low in the east |
How the phase is calculated
The phase is the angle between the Moon and the Sun measured along the ecliptic, from 0° at new moon to 180° at full moon and back. The lit fraction follows from that angle: half of one minus its cosine. At 90°, exactly half of the disc is lit, which is why that phase is called a quarter: the Moon has travelled a quarter of its orbit.
This page names a principal phase during roughly twelve hours on either side of its exact instant. Outside that window it shows crescent or gibbous, waxing or waning. That is why the Moon can look full to the eye one day before and one day after the date printed in a calendar: at 98% lit, the missing sliver is very hard to see.
Questions and answers
Is the Moon phase the same everywhere on Earth?
Yes. The phase depends on where the Moon is relative to the Sun, not on where you stand, so the whole planet sees the same fraction lit at the same moment. What changes is the calendar date (because of time zones) and the way the disc is tilted in your sky.
Why does the Moon look upside down in the southern hemisphere?
An observer in Sydney stands head-down compared with one in London. The same Moon is seen rotated by about half a turn: a waxing crescent is lit on the right in the northern hemisphere and on the left in the southern one. Near the equator it lies on its back like a bowl.
How long does each Moon phase last?
New moon, first quarter, full moon and last quarter are instants, not days. The four phases in between each last a little over seven days. The whole cycle, from one new moon to the next, takes 29.53 days on average.
What do waxing and waning mean?
Waxing means the lit part is growing, from new moon to full moon. Waning means it is shrinking, from full moon back to new moon. A waxing Moon is visible in the evening, a waning Moon late at night and in the morning.
How accurate are these numbers?
The Moon's position is computed to about one arcminute, which gives phase times and rise and set times correct to about a minute for a flat horizon at sea level. Hills and buildings on your real horizon matter more than the calculation.
Updated November 11, 2026