FREE · TIME & DATE TOOLS
Moon Phase Calculator.
Moon phase, illumination and age for any date, the next new moon, quarters and full moon in your time zone, a monthly moon calendar and every phase of the year.
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How to use Moon Phase Calculator
Pick a date and your time zone. Click any day of the monthly calendar to see it. Choose the southern hemisphere to see the moon the way it looks there (lit side reversed).
How it works
Principal phases use Jean Meeus’ algorithm (Astronomical Algorithms, chapter 49) with the periodic and planetary corrections; across 1990–2060 they agree with the astronomy-engine library within two minutes. Illumination uses chapter 48.
Example
On 14 October 2026 the moon is a waxing crescent, 13.8 % lit. The next full moon is on 26 October 2026 at 04:12 UTC (05:12 in Paris).
Questions about Moon Phase Calculator
Is Moon Phase Calculator free, and do I need an account?
Yes. This tool is free to use in your browser without an account. Processing takes place on your device.
What are the limits and what should I check?
Phase instants are accurate to about two minutes; the illumination is given at local noon. Moonrise and moonset are not calculated. Everything is calculated in your browser; nothing you type is uploaded. Review the result before using it in your work.
Is my input sent to a server?
Your input is processed in your browser and is not uploaded by this tool. Files and pasted text are cleared when the page is refreshed. Normal website requests are still required to load the page and its libraries. Read the privacy explanation.