What the score compares
Sun: who you are
Your core self and what you want out of life. Two Suns show whether you feel like the same kind of person underneath.
Moon: what you need
How you handle feelings and what makes you feel safe. Moon links decide whether home life feels easy.
Venus: how you love
What attracts you and how you show affection. Venus links show whether your love languages match.
The rising sign and the houses need an exact birth time and place, so they are not part of this score.
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How the score works
Each link is scored by how far apart the two signs sit around the zodiac. Signs of the same element score highest. Opposite signs score well, with some tension. Signs three apart score lowest, because they want different things in different ways.
| Signs | Example | Score | In short |
|---|---|---|---|
| Same sign | Aries with Aries | 82 | Instant recognition, and the same blind spots. |
| Next-door signs | Aries with Taurus | 55 | Next-door signs that need to explain themselves. |
| Two signs apart (sextile) | Aries with Gemini | 86 | Easy friendship that turns into easy love. |
| Three signs apart (square) | Aries with Cancer | 48 | Sparks, clashes and a lot of growth. |
| Same element (trine) | Aries with Leo | 94 | Same element, same rhythm. |
| Five signs apart (quincunx) | Aries with Virgo | 52 | Different wiring that takes real effort. |
| Opposite signs | Aries with Libra | 72 | Opposites with a strong pull. |
- 88 and up: Natural fit
- 78 and up: Strong match
- 68 and up: Good match
- 58 and up: Push and pull
- Under 58: Challenging
Why the birth time matters
The Moon changes sign every two to three days. If it changed sign on your birthday, the result says so and uses the sign it was in for most of the day. Add a birth time and the time zone where you were born to pin it down.
Where the positions come from
Planet positions are calculated from an astronomical ephemeris for every day from 1920 to 2050, to the minute, rather than looked up from a table of star sign dates. That is why cusp birthdays come out right.
Common questions
How accurate is compatibility by birthday?
The planet positions are exact for each date, and to the minute if you add a birth time. What they mean for a relationship is astrology, which works best as a way to reflect and talk, not as a prediction.
What if I don't know my birth time?
You still get a full result. The Sun and Venus seldom change sign on any given day, and the Moon changes about every two and a half days. If a sign changed on your birthday, the result says so and uses the sign that covers most of the day.
Why Sun, Moon and Venus?
They describe who each person is, what each needs to feel safe and how each shows love. The rising sign and the houses need an exact birth time and place, so they are left out of the score.
Does a low score mean we're doomed?
No. A low score means your signs work in very different ways, which brings more friction and more to learn. Plenty of couples with a challenging score do well because they talk about the differences.
Is my information stored?
No. Birthdays are used for the calculation and then discarded. A shared result link holds only the six signs, never a date of birth.
Your love horoscope, monthly
One email at the start of each month, written for your sign.