Moon Phase Today - Is It a Full Moon Tonight?

This Moon Phase Calendar answers one question instantly: what does the Moon look like right now, and is tonight a full moon? It shows the current phase (one of the eight principal phases), the illuminated fraction as a percentage, the Moon's age in days since the last new moon, and a live, ticking countdown to the next full moon and new moon. Everything is computed in your browser from astronomical formulas — no account, no location required, and nothing is sent to a server.

The Moon cycles through its phases over a synodic month of 29.53 days, the time from one new moon to the next. Because that cycle does not divide evenly into our 30- and 31-day calendar months, the full moon drifts a little earlier each month, which is why "is it a full moon tonight" is a genuinely useful question — the answer changes nightly. Our tool gives a clear yes or no for the current date in your local time zone, then tells you exactly how many days remain until the next one.

Beyond the live readout, the page includes the complete 2026 full moon calendar with all 13 full moons, their traditional names (Wolf Moon, Snow Moon, Pink Moon, Strawberry Moon, and so on), and markers for the year's three supermoons, the single blue moon on May 31, and two lunar eclipses. You can look up the Moon phase for any past or future date, and export every 2026 full moon to your own calendar with one click as an .ics file.

Moon phases are caused by the changing angle between the Sun, Earth, and Moon as the Moon orbits Earth. The phase depends on how much of the Moon's sunlit half faces us. At new moon the Moon sits between Earth and Sun (0% illuminated); at full moon Earth lies between them (100% illuminated). The illuminated fraction is calculated from the phase angle i using the formula illumination = (1 + cos i) / 2.

A critical detail most simple calculators get wrong: the full moon is an instant, not a whole day. It is the precise moment the Moon reaches 180° of elongation from the Sun. A linear approximation based on the average 29.53-day cycle can be off by a full day near that instant, which would make a "full moon tonight" answer simply wrong. This tool instead uses the Jean Meeus algorithm from Astronomical Algorithms, which includes dozens of periodic correction terms and matches the U.S. Naval Observatory to within about one minute.

The synodic month is not constant — it varies between roughly 29.27 and 29.83 days because the Moon's orbit is elliptical and perturbed by the Sun. That variability is exactly why precise computation matters. All phase instants here are calculated in Universal Time and then converted to your local time zone, so the date shown always matches your own calendar day.