Methodology
How We Calculate Scores and Matches
How Mirror computes zodiac compatibility scores, links MBTI and Enneagram types to Sun signs, and dates its horoscope pages, with the exact rules we use.
Updated October 29, 2026
Zodiac compatibility scores
Every zodiac pairing on our compatibility pages has a score out of 100, plus four category scores: love, friendship, communication and trust. They come from a fixed formula, not from a writer's opinion, so the same two signs always get the same numbers.
The starting point is the aspect: how many signs apart the two are on the zodiac wheel. Classical astrology treats trines and sextiles as easy, and squares and quincunxes as tense.
Each category then adjusts that base for element, modality and ruling planets, using the rules below. Scorpio, Aquarius and Pisces count both their traditional and modern rulers. Every score is kept between 30 and 97, and the overall score is the average of the four categories.
These are Sun-sign scores only. A full comparison of two birth charts (synastry) looks at the Moon, Venus, Mars, the rising sign and the houses, and can tell a very different story.
| Aspect | Distance | Base score |
|---|---|---|
| Trine | 4 signs apart, same element | 88 |
| Sextile | 2 signs apart | 82 |
| Conjunction | the same sign | 72 |
| Opposition | 6 signs apart | 68 |
| Semi-sextile | next to each other | 52 |
| Square | 3 signs apart | 48 |
| Quincunx | 5 signs apart | 44 |
| Category | Adjustments to the base score |
|---|---|
| Love | +10 for an opposition, +4 when both signs are earth or water and at least one is water, +3 when Venus rules either sign |
| Friendship | +6 for a sextile, +4 when both signs are fire or air, +3 when Jupiter rules either sign, -4 when both signs are cardinal |
| Communication | +5 when either sign is air or ruled by Mercury, +3 when both are mutable, +3 for the same sign |
| Trust | +6 when both signs are earth or water, +3 when either is fixed, -4 when both are mutable, -3 for the same sign, -3 when Jupiter rules either sign |
MBTI and Enneagram types for each sign
Our zodiac, MBTI and Enneagram pages say which personality types fit each Sun sign best, and which fits least. No research links personality types to Sun signs. These matches are our reading of where the two descriptions overlap: a sign described as patient and practical lines up with types built around steady, concrete thinking.
One idea we use often comes from the astrologer Liz Greene (Relating, 1977), who paired the four elements with Carl Jung's four functions: fire with intuition, earth with sensing, air with thinking and water with feeling. Where that function sits in a type's function stack tells us whether the sign's element comes easily to that type or is something they grow into.
Every page draws on the same table of matches, so the sign page, the type page and each combination page agree with each other.
Dates for horoscopes, retrogrades and eclipses
The dates on our yearly horoscope, Mercury retrograde and eclipse pages are calculated, not copied. We compute planetary positions with Astronomy Engine, an open-source astronomy library, and list each ingress, station and lunation in Coordinated Universal Time (UTC). Where an eclipse can be seen comes from NASA's published eclipse tables.
The interpretations on those pages are astrology, not astronomy. The dates are as exact as we can make them. What they mean for you is a matter of tradition and belief.
What these numbers can't tell you
Astrology isn't a science, and personality types describe preferences, not abilities. Use the scores and matches as a way to think about yourself and the people you care about, not as a verdict on a relationship or a career.
We never cite studies, statistics or user data we don't have. If a page says something about how common a mix is, it's describing how well the two descriptions fit, not how many people have it.
Corrections
If you find a date, rule or fact that looks wrong, tell us and we'll check it against the method above and fix it.
Read how we write and check our pages in our editorial policy.