How Synastri Actually Calculates Your Compatibility Score
Zodiac compatibility isn't a scientifically validated predictor of relationship success, but the score itself isn't a random guess either — it's deterministic: the same two signs always produce the same numbers, computed from three real pieces of astrology.
The three building blocks
Every pair score starts from three real, checkable inputs: the angular distance between the two signs on the zodiac wheel (their "aspect" — conjunction, sextile, square, trine, and so on), whether their elements pair well (fire and air, or earth and water, traditionally flow more easily than fire and water), and whether their modalities match (cardinal, fixed, or mutable). None of these depend on birth time, name, or anything random — only on the two signs themselves.
How the blend works
The overall score weights aspect most heavily, then element, then modality, plus a small fixed adjustment tied to the specific pair of signs so that pairs sharing the same aspect distance (say, two different trine pairs) don't all read as identical. The spark, communication, and trust sub-scores each reweight the same three ingredients differently — communication leans harder on modality and gets a boost when air is involved, trust leans on aspect plus whether earth or water is present. Nothing here is re-rolled between visits: the same sign pair always returns the same numbers.
Check your own
Synastri's `/compat` calculator runs this exact aspect/element/modality blend on your real signs — no randomized draw, no name numerology folded in, just the documented astrology described above. For entertainment, not a scientifically validated predictor of relationship outcomes.