Star twin: which celebrity shares your birth sky
Enter your date of birth. We calculate where the Sun, Moon, Mercury, Venus and Mars stood and show two lists: celebrities born on the same day as you, and those whose sky matches yours most closely in other years. No birth time or city needed.
This is entertainment built on real calculations. Two similar charts do not mean similar fates, characters or success: a birth sky cannot predict a life. But five fast planets lining up is rare, and it is fun to see who it happens with.
How we score similarity
For your date of birth the Swiss Ephemeris gives the longitude of five fast planets: the Sun, Moon, Mercury, Venus and Mars. The same longitudes are calculated for the celebrity charts in our database.
For each planet we take the distance between your point and the celebrity point around the zodiac circle. The smaller it is, the higher the closeness: an exact match scores the maximum and a distance beyond the range scores zero. The result is a weighted average over the five planets, as a percentage.
We use only the fast planets. The slow ones are shared by a whole generation: Neptune in Capricorn is true for almost everyone born from 1984 to 1998 and says nothing about a twin. Fast planets travel the whole circle in a year, so lining up on all of them is rare.
We do not compare the Ascendant or houses: most celebrities have no confirmed birth time, and without it they cannot be calculated.
That is why there are two lists. People born on the same date almost always score high: the fast planets barely move in a day. People born in another year match only if the sky repeated, which is rare. Anyone born within two days of your date is left out of the other-year list: they are almost indistinguishable from people born on the same day.
Range and weight of each planet
| Planet | Range | Weight |
|---|---|---|
| Sun | 4° | 3 |
| Moon | 12° | 1.5 |
| Mercury | 5° | 1.5 |
| Venus | 5° | 2 |
| Mars | 6° | 1.5 |
Want to see your real chart?
The twin compares only five planets. A full natal chart shows the Ascendant, houses and aspects, and AI writes the reading in one of three tones. We calculate it with the Swiss Ephemeris.
Calculate your natal chartStar twin questions
What does the similarity percentage mean?
It is a weighted closeness of five fast planets. 100% means all five stand at the same points. A high score is expected for people born on the same day as you: the fast planets barely move in a day. For people from other years it is lower, and that is normal.
Is someone born on the same day and month, a year earlier or later, a twin?
No. Take 29 May 1985 and 29 May 1986: the Sun is the same (a gap of 0.2 degrees), but the Moon differs by 141 degrees, Venus by 76 and Mars by 150, for a score of 30%. Only the Sun matches, because it returns to the same point every year. The other planets travel far in a year.
Why are Jupiter, Saturn and the outer planets left out?
They are slow: Jupiter spends a year in a sign, Saturn two and a half, and the outer planets decades. Everyone of your age shares them, so they do not help find a true twin.
Do I need my birth time and place?
No, a date is enough. Without a time we calculate the Moon for noon Greenwich time and compare it with a 12 degree margin. A time is needed only for the Ascendant and houses, which we do not compare here.
Where do the celebrity birth dates come from?
From open databases: for some people the date is confirmed by a source (for example Wikidata or Astro-Databank), for the rest it comes from our catalogue. Placeholders such as 01.01 and dates we found to be wrong are excluded from the search.
Do my star twin and I share a fate?
There is no basis for that. It is a game built on real calculations, not a scientific claim. If you are interested in astrology as a language for describing character, open a full natal chart and reading.
Do you store my date of birth?
No. The date is sent for the calculation and is not stored: the page needs no sign-up and writes nothing to your account.