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Black Moon Lilith calculator
Enter your birth date and see where your Black Moon sits. An exact time is only needed for the house — the sign works without it.
Lilith in brief
What the Black Moon is, and why sites disagree about it
Lilith is not a planet or an asteroid. It is a geometric point: the spot on the Moon's orbit furthest from Earth. You cannot see it through a telescope, so there is no observed position to settle the argument — only a chosen way of counting.
- An apogee, not a body
- The Moon travels around Earth on a stretched orbit. The near point is the perigee, the far one is the apogee. Astrologers call the longitude of that apogee the Black Moon, or Lilith.
- Two conventions, not one
- The apogee can be taken as an average over the cycle or as the real one at a given minute. The first gives mean Lilith, the second gives true Lilith. Both are valid, and they return different numbers.
- A gap as wide as a sign
- Mean and true Lilith can sit up to 30° apart — exactly the width of a zodiac sign. That is why the same person sees two different signs on two different sites and assumes one of them is wrong.
- When the birth time matters
- The sign works from the date alone: mean Lilith covers only about 0.111° in a day. The house is another matter — it is measured from the Ascendant, which shifts about a degree every four minutes.
Questions
Common questions about Lilith
Can I find my Lilith sign without a birth time?
Yes, the sign you can. Mean Lilith moves about 0.111° a day, so across a whole day it barely shifts and the sign stays the same. The house is a different matter and needs an exact time, because houses are measured from the Ascendant, which travels the full circle every day. If you were born on a day when Lilith crossed between signs, the calculator flags that separately.
Why does another site give me a different Lilith sign?
Most likely it is showing the other Lilith. Mean and true are two ways of calculating the same point, and they sit about 11° apart on average, sometimes almost 30°. They fall in different signs for roughly one person in three. That is exactly why we show both numbers at once, instead of one number with no explanation.
Which Lilith is the correct one, mean or true?
Astronomically both are correct: they are different conventions, not accuracy versus error. The Western tradition tends to use mean Lilith because it moves evenly and its position is stable. True Lilith describes the orbit more precisely at a given moment, but it wobbles and spends most of its time retrograde. Choosing between them is a matter of school, not of calculation.
Is Lilith part of your natal readings?
No. SidusVita readings are built on thirteen points: the Sun, the Moon, the Ascendant, the planets from Mercury to Pluto, and the lunar nodes Rahu and Ketu. The Black Moon is calculated here, in this tool, and nowhere else. We would rather read the points we do use in depth than list more of them for completeness.
What does Lilith show in a chart?
In astrological tradition the Black Moon is linked to what has been pushed aside: the part of yourself you do not admit to, which shows up anyway. The sign describes the area it lives in, the house shows where in life it switches on. This is a language of interpretation rather than a measurable trait, and it is worth reading in that spirit.
Do you store the birth data?
No. This calculator runs without a signup: the date, time and coordinates are used at the moment of calculation and are never written down. Only the charts you create after signing in are saved to your account.
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