Moon Phase Calculator — Free Online Tool

See the moon phase, illumination and lunar age for any date with an emoji icon. Moon Phase Calculator is a free online tool from the ToolsRift Everyday Tools collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.

Loading Moon Phase Calculator…

How to use Moon Phase Calculator

  1. Open the Moon Phase Calculator above — it loads instantly, no account needed.
  2. Enter or upload your input. Everything is processed locally on your device.
  3. Get your result immediately and copy or download it with one click.

Frequently asked questions

How accurate is the moon phase?

It uses the average synodic month (29.53 days) from a known new moon, so it is accurate to within roughly a day — great for a quick reference, planning or curiosity.

What are the eight phases?

New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter and Waning Crescent — the full cycle repeats about every 29.5 days.

What does illumination mean?

It is the fraction of the Moon's visible disc lit by the Sun — 0% at new moon, 100% at full moon.

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