Calculate the moon phase for any date. View the lunar phase name, illumination percentage, moon age, and a 7-day moon calendar. Pure client-side.
This moon phase calculator determines the lunar phase for any date using astronomical algorithms. It calculates the moon's illumination percentage, age in days, and phase name. The tool also shows upcoming new moon and full moon dates, plus a 7-day calendar view. All calculations happen in your browser — no data is sent to any server.