🌙Moon Phase Calculator
Enter any date to see the Moon's current phase, illumination, age in the cycle, and when the next new and full moon occur.
Free Moon Phase Calculator
This free Moon Phase Calculator tells you the Moon's phase for any date you enter — showing the phase name (one of eight phases from New Moon to Waning Crescent), the illumination percentage, the Moon's age in days within the current synodic cycle, and whether the Moon is currently waxing (growing brighter) or waning (growing darker). A visual moon graphic updates to reflect the lit and dark portions for your chosen hemisphere.
Use it to plan around the next full moon or new moon, to look up the Moon phase on a birthday or historic date, or to settle a friendly debate about what phase is happening tonight. Switch between Northern and Southern hemisphere view — because from the Southern Hemisphere, the lit crescent appears on the opposite side. The dates of the next new moon and full moon are shown below the main result so you can plan ahead for stargazing, photography, or simply satisfying curiosity.
No sign-up, no downloads, and no data leaves your browser — the entire calculation runs locally in JavaScript. For more detail on how the calculation works, see the About page, and for common questions see the FAQ.