Moon Phase Calculator

Exact phase · illumination % · any date

Enter any date to see the precise moon phase from live astronomical calculations, not a static table.

The Moon completes eight phases every ~29.5 days. This tool calls the same live ephemeris used by the Natal Echo cosmic calendar, so you get the exact phase for any date, not just the four quarter milestones.

Try your birthday, a wedding date, or today to see how much of the disc is illuminated and whether the Moon is building or releasing.

How to Use the Moon Phase Calculator

Find the lunar phase for any date including birthdays and special events.

  1. 1. Pick a date using the date picker (today is selected by default)
  2. 2. View the moon phase name, emoji, illumination percentage, and waxing or waning status
  3. 3. Use the result for rituals, gardening by the moon, or birth chart curiosity

Related guides

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FAQ

How accurate is this moon phase calculator?

Phases are computed from NASA JPL-validated astronomical models via our live API, updated for the exact date you enter.

Can I look up the moon phase on my birthday?

Yes. Enter any past or future date in YYYY-MM-DD format to see the phase that was or will be in the sky.

What is moon illumination percentage?

Illumination is how much of the Moon's disc appears lit from Earth, from 0% at new moon to 100% at full moon.