Moon Phase Calculator
See today's lunar phase, illumination percentage, and upcoming full and new moons. Pick any date to look up the phase for that day.
Right now
Waning Crescent
8.6% illuminated · 26.7 days into the cycle
Look up a date
Waning Crescent
11.8% illuminated
Upcoming full moons
- Wed, Jul 29, 20261:23 PM
- Fri, Aug 28, 20262:07 AM
- Sat, Sep 26, 20262:51 PM
- Mon, Oct 26, 20263:35 AM
- Tue, Nov 24, 20264:19 PM
- Thu, Dec 24, 20265:03 AM
Upcoming new moons
- Tue, Jul 14, 20267:01 PM
- Thu, Aug 13, 20267:45 AM
- Fri, Sep 11, 20268:29 PM
- Sun, Oct 11, 20269:13 AM
- Mon, Nov 9, 20269:57 PM
- Wed, Dec 9, 202610:41 AM
About moon phases
A lunar cycle — from one new moon to the next — averages 29.53 days. Halfway through, the moon is full; the quarters fall a week before and after. This calculator anchors to a known reference new moon and steps forward by the mean synodic month, which is accurate within a few hours for everyday use.
Frequently asked questions
- How accurate are the moon phases?
- Within a few hours of NASA reference dates. The calculator uses the mean synodic month (29.530588853 days) anchored to a known new moon, which is accurate enough for calendars and planning but not for eclipses.
- What does illumination percentage mean?
- The fraction of the moon's Earth-facing disc lit by the sun. 0% is a new moon, 50% is a first or last quarter, and 100% is a full moon.
- Do the times account for my time zone?
- Yes — full and new moon dates are formatted in your device's local time zone.