Moon Phase Calculator — Find the Moon Phase for Any Date

A full Moon is spectacular to look at but terrible for deep sky observing — it washes out faint nebulae and galaxies. A new Moon gives the darkest skies of the month. Knowing where the Moon is in its cycle helps you plan everything from telescope sessions to nightscape photography.

Find the Moon phase for any date with the moon phase calculator on CalcHub.

The Lunar Cycle

The Moon completes one full orbit around Earth every 27.3 days (sidereal period). But because Earth is also moving around the Sun, the Moon needs a bit longer — 29.5 days — to return to the same apparent position relative to the Sun as seen from Earth. This 29.5-day synodic period is the lunar month.

The Eight Moon Phases

Phase	Illumination	When It Rises	When It Sets
New Moon	0%	Sunrise	Sunset
Waxing Crescent	1–49%	Morning	Evening
First Quarter	50% (right side)	Noon	Midnight
Waxing Gibbous	51–99%	Afternoon	After midnight
Full Moon	100%	Sunset	Sunrise
Waning Gibbous	99–51%	Evening	Morning
Last Quarter	50% (left side)	Midnight	Noon
Waning Crescent	49–1%	Pre-dawn	Afternoon

How to Use the Calculator

1. Enter a date (past, present, or future)
2. Get the Moon phase, illumination percentage, and days since new Moon
3. See the next upcoming new Moon and full Moon dates

The CalcHub calculator also shows the rise and set times for your latitude — useful for planning observing windows.

Moon Phases and Deep Sky Observing

The Moon's light is roughly 400,000 times fainter than the Sun, but against a dark sky it's bright enough to reduce limiting magnitude significantly. Within a few nights of full Moon, faint objects like the Veil Nebula or M33 become much harder to detect. Experienced observers plan sessions around new Moon — typically the 7–10 days centered on new Moon give the darkest skies.

Bright objects — open clusters, the Orion Nebula, the planets — can be observed at any Moon phase. The Moon's light doesn't affect them meaningfully.

Lunar Photography

Full Moon images are actually less dramatic than people expect because the straight-on lighting flattens all the craters. The most visually interesting lunar surface photography happens near the terminator line — the boundary between light and shadow — during crescent or quarter phases. Long shadows cast by crater walls create dramatic three-dimensional texture.

For nightscape photography (landscape with the Milky Way), a new Moon is essential. The Milky Way is completely invisible from most locations when the Moon is up.

Does the Moon affect tides every phase?

All Moon phases create tides, but the largest tides (spring tides) occur at new Moon and full Moon, when Earth, Moon, and Sun align and their gravitational effects reinforce each other. Quarter Moons produce neap tides — the Sun and Moon are at right angles, partially canceling each other's tidal pull.

Why does the Moon always show the same face to Earth?

The Moon rotates once on its own axis in the same time it takes to orbit Earth once — a condition called tidal locking, caused by millions of years of gravitational interaction. The same 59% of the Moon's surface is always visible from Earth (a bit more than half due to "libration" — a slight wobbling that allows us to peek around the edges).

Is there really a "dark side of the Moon"?

Technically, no — every part of the Moon receives sunlight at some point during the lunar month. The "far side" is simply the hemisphere that always faces away from Earth. It does experience night and day just like the near side. It was first photographed in 1959 by the Soviet Luna 3 spacecraft.

Related Calculators

• Sunrise/Sunset Calculator — plan observing windows by daylight
• Telescope Magnification Calculator — optimize your observing setup
• Star Magnitude Calculator — see how Moon phase affects limiting magnitude