How do I calculate the moon phase for a specific date?

Enter the date above — we compute the angle between the Sun and Moon on that day and map it to one of the eight moon phases (New, Waxing Crescent, First Quarter, Waxing Gibbous, Full, Waning Gibbous, Last Quarter, Balsamic). All Swiss-Ephemeris accurate and free.

What does my birth moon phase mean?

The moon phase at your birth describes a core thread of your nature — from the instinctive New Moon person to the expressive Full Moon soul. It adds another, often surprisingly accurate layer on top of your Sun sign and Moon sign.

Does the moon phase depend on location?

The phase itself (New, Full …) is the same worldwide, because it only depends on the angle between the Sun and Moon. Only the exact time of the change shifts slightly by time zone. So for a birth moon, the date alone is enough.

What’s the difference between moon phase and moon sign?

The moon phase is how full the moon is (the cycle from New to Full). The moon sign is which zodiac sign the Moon is in. Both belong to the Moon but describe different things — the phase your emotional dynamic, the sign your emotional nature.

Is the moon phase calculator free?

Yes, completely — no sign-up, no card. If you want to learn to read your whole moon (phase, sign, house) yourself, that’s what our 30-day guide is for.

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Astrology · Moon phase

Which moon phase
were you born under?

Enter a date — today, your birthday or any other day — and we’ll show you the exact moon phase with a clear reading. Swiss-Ephemeris accurate, free, no sign-up. Find out which moon you were born under.

For your birth moon, just enter your date of birth — no time or place needed.

How it works

Your moon phase in three steps

Pick a date
Type any date — today is pre-filled. For your birth moon, use your date of birth.
Compute the phase
We measure the angle between the Sun and Moon with the Swiss Ephemeris — the same basis professional software uses.
Read the meaning
You get the phase with its symbol and a clear reading — both as today’s energy and as a birth-moon character.

The basics

What is a moon phase?

The moon phase is the shape of the lit part of the Moon as it moves through a full cycle in about 29.5 days — from New Moon through Full Moon and back. Astrologically it’s measured by the angle between the Sun and Moon: at 0° they sit together (New Moon), at 180° opposite (Full Moon). That angle is what defines the eight classic phases.

What your birth moon means

The phase you were born under adds its own layer to your chart — on top of your sun sign and moon sign. A New Moon person tends to be instinctive and quick to begin; a Full Moon person is expressive and lives in relationship; the waning phases bring maturity, release and passing things on. It’s not about "good" or "bad" — it’s about your natural rhythm.

Don’t confuse the moon phase with the moon sign: the phase is how full the Moon was (your emotional dynamic), the sign is which zodiac sign it was in (your emotional nature). Both belong to the Moon but describe different things.

Moon phase questions

How do I calculate the moon phase for a specific date?: Enter the date above — we compute the angle between the Sun and Moon on that day and map it to one of the eight moon phases (New, Waxing Crescent, First Quarter, Waxing Gibbous, Full, Waning Gibbous, Last Quarter, Balsamic). All Swiss-Ephemeris accurate and free.
What does my birth moon phase mean?: The moon phase at your birth describes a core thread of your nature — from the instinctive New Moon person to the expressive Full Moon soul. It adds another, often surprisingly accurate layer on top of your Sun sign and Moon sign.
Does the moon phase depend on location?: The phase itself (New, Full …) is the same worldwide, because it only depends on the angle between the Sun and Moon. Only the exact time of the change shifts slightly by time zone. So for a birth moon, the date alone is enough.
What’s the difference between moon phase and moon sign?: The moon phase is how full the moon is (the cycle from New to Full). The moon sign is which zodiac sign the Moon is in. Both belong to the Moon but describe different things — the phase your emotional dynamic, the sign your emotional nature.
Is the moon phase calculator free?: Yes, completely — no sign-up, no card. If you want to learn to read your whole moon (phase, sign, house) yourself, that’s what our 30-day guide is for.

What you get

Your moon, for any day

The exact phase
From New Moon to Full Moon — we compute the precise phase for your date, with its symbol and name.
Your birth moon
Which moon phase were you born under? Read what it says about your nature — the most popular way to look at your moon.
A clear reading
Every phase gets a plain-language meaning — as today’s energy, and as a character trait if you were born under it.
Any date
Past, present or future. Check the moon for a wedding day, a big meeting, or simply tonight.