Moon Phase Today

What is a moon phase?

The moon doesn't make its own light — it reflects the sun. As the moon orbits Earth, the angle between the sun, moon and us changes, so we see different amounts of its lit half. That changing shape is the moon phase. When the moon sits between Earth and the sun we see its dark side (new moon); when Earth sits between them, the whole lit face turns toward us (full moon).

The eight phases of the lunar cycle

The cycle runs through eight recognisable stages. It begins at the new moon and grows — waxing — through a thin crescent to the first quarter (half lit), then a bulging gibbous, up to the full moon. From there it shrinks — waning — back through gibbous, the last quarter, a final crescent, and around to new again. The whole loop takes about 29.53 days, the synodic month. A handy trick in the northern hemisphere: if the lit side is on the right, the moon is waxing; on the left, it's waning.

Full moon, new moon and moon age

"Moon age" counts the days since the last new moon, so 0 days is new, about 7.4 days is first quarter, roughly 14.8 days is full, and about 22.1 days is last quarter. Above, you'll find live countdowns to the next full moon and the next new moon — useful for planning stargazing (dark skies near new moon), photography, tides, gardening by the lunar calendar, or simply knowing when the night will be brightest.

How this moon phase tracker works

The illustration is drawn from the moon's real illuminated fraction for the current moment, and it updates live. Use the day arrows to look ahead or back, and set your location to see whether the moon is currently above or below your horizon. Everything is computed in your browser using standard astronomical formulas — no ads, no account, and it works offline once loaded.