How to use
- 1
Pick a date and time. The tool opens on the current moment in your own time zone.
- 2
Change the time zone if you want the phase for another place, for example your birthplace.
- 3
Switch to the Southern Hemisphere view if you live south of the equator, where the Moon appears mirrored.
- 4
Read the phase, illumination, age and sign, then check the month grid for new and full moon days.
How the phase is calculated
The phase depends on the angle between the Sun and the Moon as seen from Earth. At 0° the Moon stands between us and the Sun (new moon), at 90° it is half lit (first quarter), at 180° it is opposite the Sun (full moon) and at 270° it is half lit again (last quarter). The calculator computes that angle from precise planetary theory for the exact minute you choose, so the illumination percentage and the times of the next phases are astronomical values, not table approximations. A moment is labelled with a main phase only when it lies within about twelve hours of the exact phase; otherwise you see the in-between phase, such as waxing gibbous.
Moon age, distance and the lunar month
Moon age is the time since the last new moon. One full cycle, the synodic month, averages 29.53 days but varies by several hours from one month to the next because the Moon’s orbit is elliptical. The same ellipse explains the distance figure: the Moon swings between roughly 356,000 and 407,000 km from Earth, which is why some full moons look slightly bigger and brighter than others.
Northern and Southern Hemisphere view
In the Northern Hemisphere a waxing Moon is lit on the right and a waning Moon on the left. South of the equator observers face north to see the Moon, so the picture is mirrored: the waxing crescent is lit on the left. The phase, percentage and times are the same everywhere; only the orientation of the drawing changes.
The Moon’s sign in astrology
The Moon moves through all twelve zodiac signs in about 27.3 days, spending roughly two and a half days in each. The calculator shows its tropical sign and degree, the system used in Western astrology, where the Moon is associated with emotions, habits and the inner world. Many people use the Moon’s sign together with its phase as a prompt for reflection; it is a symbolic tradition, not a forecast.
Frequently asked questions
What is the moon phase today?
The calculator opens on the current date and time in your browser’s time zone, so the first result you see is today’s phase, with the percentage of the disc that is lit and the Moon’s age in days.
Why does the Moon look different in Australia?
Seen from the Southern Hemisphere, the Moon is upside down compared with the northern view, so a waxing crescent is lit on the left instead of the right. Use the hemisphere switch to see the correct orientation.
How accurate are the phase times?
The times come from a full astronomical model of the Sun and Moon and are accurate to about a minute. They are geocentric, the standard used in calendars and almanacs.
Is a full moon on the same night everywhere?
The full moon is a single instant worldwide, but the local date depends on the time zone. A full moon at 02:00 UTC on the 15th falls on the evening of the 14th in the Americas. Change the time zone to see the local date.