Moon phase calculator
Pick a date to see the moon’s phase, illumination and age - plus the next full moon and new moon dates. Quick, honest night-sky planning with no location needed.
Date
The phase is shown for the whole selected day in your device’s time zone.
No moonrise or moonset is given here - this is a phase and brightness planner only.
Moon on this date
How it works
The phase is computed from the moon’s age in the synodic month - the 29.53-day cycle from one new moon to the next - using the standard Meeus-style approximation. The calculator finds where the selected date falls in that cycle and reports the phase name, the fraction of the disc that is lit, and the age in days since the last new moon. It then steps forward around the cycle to show the dates of the next full moon and new moon.
No location is needed because phase, illumination and age are essentially the same for every place on Earth - only moonrise and moonset times vary by location, and this tool deliberately does not try to estimate those.
Why the moon matters for photography
- A new or young moon means dark skies - the best time for the milky way and faint star trails.
- A full moon lights the landscape and can be a subject itself, but it washes out the faint milky way core.
- Between roughly last quarter and new moon, the moon rises late or not at all, giving dark pre-dawn windows.
- Waxing to first quarter, the moon sets around midnight - good for a late-evening dark-sky window afterwards.
Example
On 3 January 2026 the calculator reports a Full Moon at about 99.6% illumination and an age of roughly 14 days. The next new moon follows around 18 January 2026 - a good target for a dark-sky night. Dates are approximate to about a day.
Related sky planning
Dark skies only help if the moon is down when you shoot - check the milky way planner. For the surrounding light windows see the golden hour and sunrise & sunset calculators.
Frequently asked questions
What do the moon phase names mean?
The eight main phases follow the moon's orbit around Earth: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter and Waning Crescent. Waxing means the lit side is growing towards full; waning means it is shrinking towards new.
What is moon age?
Moon age is roughly the number of days since the last new moon. The full cycle from new moon to new moon is about 29.5 days (the synodic month), so the age runs from near 0 at new moon to near 29.5 just before the next new moon.
How accurate is the illumination percentage?
Illumination and phase are computed from the standard synodic-month approximation, so they are accurate to roughly a couple of percentage points and the phase date is usually right to about a day. For precise rise, set and exact percent values, use an astronomy app.
Why is moonrise and moonset not shown?
Moonrise and moonset depend on the moon's position in the sky, which this simple phase approximation does not model. This calculator answers the planning question that matters most for night photography: how bright is the moon and is it growing or fading?