How to use it
- Choose the date you want. The page starts with today.
- Read the phase name and the lit share. The drawing shows how the lit part is turned.
- Read the age and the sign to see where the Moon is in the zodiac at noon of that day.
- Use the list of next phases to plan a date, and tick Show times in UTC if you want Universal Time.
How the phase is found
The phase depends on the angle between the Sun and the Moon as seen from the Earth. Measured along the ecliptic, that difference is 0 degrees at a new moon, 90 at a first quarter, 180 at a full moon and 270 at a last quarter. The page names the phase in eight bands of 45 degrees between those points.
The lit share is the fraction of the disc that faces the Sun. It is 0 percent at new moon, half at each quarter and 100 percent at full moon. The age is the time since the last new moon, counted in days.
phase = Moon's longitude − Sun's longitude (degrees)
lit share = (1 + cos(phase angle)) ÷ 2The sign and the zodiac
The sign is the part of the tropical zodiac, a division of the ecliptic into twelve signs of 30 degrees that starts at the spring equinox. It is a position measured by astronomy; the meanings that astrology gives to a sign are a tradition and are not shown here.
What this page does not show
- The Moon's position at other hours of the day. The page uses noon in your time zone.
- Whether the Moon is above the horizon where you are, and the times it rises and sets.
Worked example: 26 January 2026
On 26 January 2026 the Moon is at its first quarter. At noon in Istanbul (09:00 UT) its phase is First quarter, and 52.1 percent of the disc is lit.
The Moon is then 7.5 days old, in Taurus at 8° 42′. The next principal phases are the full moon on 1 February 2026 at 22:09 UT, the last quarter on 9 February at 12:43 UT, the new moon on 17 February at 12:01 UT and the first quarter on 24 February at 12:28 UT.
Frequently asked questions
Why does the phase name differ from the percentage shown?
The name follows the angle between the Sun and the Moon, and the percentage is the share of the disc that is lit. At a quarter the share is about half, but a crescent or a gibbous moon can have a similar share at different angles.
What is the difference between a waxing and a waning moon?
A waxing moon is growing, between a new moon and a full moon, and is lit on the right in the northern hemisphere. A waning moon is shrinking, between a full moon and the next new moon, and is lit on the left.
How accurate are the phase times?
The times agree with the US Naval Observatory's published phase times to within about a minute in the checks made for this page.
Why is the Moon's sign different from its phase?
The phase measures the Moon's angle from the Sun, and the sign measures where it is against the stars' background. The Moon moves about 13 degrees a day, so it changes sign about every two to three days.
Is the age of the Moon the same as the day of the lunar month?
Almost. The age counts the time since the last new moon exactly, to the fraction of a day, so it is the same as the day of the lunar month only when the date is taken at the same time of day.
Sources
- US Naval Observatory: Phases of the Moon, the definitions and times used to check the page
- astronomy-engine, the open-source astronomy library (MIT) that computes the Moon's position and phases
Figures and text last checked on Tuesday, November 10, 2026.