Compatibility, in six dimensions — including the one most reports skip.

How synastry actually works

Synastry is the technical name for reading two natal charts against each other. The first chart is laid out as normal — Sun, Moon, planets, houses, aspects. The second chart is then overlaid: each of their planets is read against your chart, and each of your planets is read against theirs. The aspects between the two charts — the geometric angles between, say, their Mars and your Venus — describe the dynamic between the two people in characteristic ways. A close conjunction at low orb is loud; a wide square is quieter but persistent.

The houses do a second, often-underread layer of work. When their Sun lands in your seventh house, the dynamic between you carries a specific kind of partnership weight; when it lands in your twelfth, the dynamic carries the texture of solitude shared in proximity. The houses tell you which arena of life each of their planets is showing up in for you, and vice versa. That is where most of the day-to-day texture of the relationship actually lives — more than in the romantic Venus-Mars conjunctions that compatibility sites lead with.

Finally, the composite. The composite chart is a third chart made from the midpoints between your two charts — not your chart, not theirs, but the relationship's chart, treated as its own thing. The composite reads as a separate dreamer: it has its own Sun, Moon, Ascendant, and aspects. Many long-running pairs find the composite easier to read than either of their individual charts, because the relationship has a life of its own that neither person can quite see from the inside.

What a compatibility report is not

Not a verdict. A low overall score does not mean the relationship will fail; a high score does not mean it will succeed. Many enduring relationships read low on synastry — the friction is present and the people in the relationship have found a way to work with it. Many bright early-stage relationships read high and burn out anyway because the people in them did not put the work in. The report names the texture; the people in the relationship live the rest.

Not a green-light / red-light filter. The dictionary does not treat compatibility as a pre-screen for whether to stay or leave. Both decisions are bigger than the data we have; the report is one input into a decision the people in the relationship are the only ones authorised to make.

Not a horoscope match. Sun-sign compatibility tables — Aries-Aquarius, Libra-Cancer — are not in the dictionary's house style. They are calibrated against twelve buckets when the actual compatibility data lives in hundreds of bilateral aspects between two specific charts. A Sun-sign compatibility table is the weather forecast for everyone in the country; this report is the weather forecast for the room you are actually in.

The six dimensions, in detail

The report measures six things. They are not weighted equally; the writer-up calls out which dimensions are doing most of the work for each specific pair.

Conflicts — what the friction is, and how big

The dimension shown free. Most compatibility tools lead with Romance to keep readers happy; this one leads with Conflicts on purpose, because the question that brought most readers to a compatibility tool is whether the friction in the relationship is real and how big it is. Conflicts is read off the hard aspects between the two charts — squares and oppositions between Mars, Saturn, and Pluto are the dominant signal. A high Conflicts score is not a sentence; it is a description of where the work is.

Romance — the attractor pattern

What pulls the two of you toward each other. Venus and Mars between the charts do most of this work — Venus describes what each of you finds attractive, Mars describes what each of you reaches for, and the aspects between them describe the chemistry. A high Romance score with a low Long-term sustainability score is a familiar early-stage pattern; reading them side-by-side keeps the conversation honest about which phase of the relationship the score is describing.

Communication — defaults and translation

Mercury between the charts. Whether you understand each other's defaults or have to translate. Two charts with Mercuries in the same element rarely need translation; two charts with Mercuries in opposing elements will have to. Communication scores can be improved by deliberate work in ways some of the other dimensions cannot — the pair learns to translate. The score is the starting point, not the destination.

Long-term sustainability — the Saturn read

Where Saturn does most of the work. Saturn between the two charts describes whether the structure of the relationship holds after the first three years — when the chemistry naturally cools and the question becomes whether the structure underneath was strong enough to carry the relationship through. This dimension is weighted heavily in the overall score because the literature is fairly clear: it is the best predictor of relationship endurance.

Intimacy — emotional and physical closeness

The Moon and Venus do most of this work. Whether the emotional closeness is easy or requires effort, and whether the physical closeness lines up with the emotional. Two charts can be intimate in one register and distant in the other; the report reads the two registers separately so the pair can see which is doing the work.

Values — what each of you reaches for

Jupiter and the second house. What each of you takes seriously, what each of you reaches for, where each of you spends time and money when no one is asking. Two people with aligned Values can have a hard time on every other dimension and still find their way; two people with misaligned Values often struggle even when everything else reads well. This is the dimension whose absence is hardest to compensate for.

How to read your report

Start with the dimension you came to ask about. If you opened the report because the friction in the relationship has been heavy, read Conflicts first. If you opened it because you cannot tell whether the early excitement is going to last, read Romance and Long-term sustainability side by side. Reading in question-driven order is more useful than reading top-to-bottom.

Then look at where the dimensions disagree with each other. A high Romance and low Communication is a common early-stage pattern. A high Long-term and low Romance is a common later-stage pattern. The disagreements are where the most information is — when two dimensions agree, they confirm each other; when they disagree, they name a specific texture the relationship has.

Then read the synastry summary. The summary aggregates the aspect-by-aspect work into a short paragraph; it is the version of the reading that fits in a phone notification. Many readers come back to the summary repeatedly and dip into the dimensions when they need the detail.

Finally, if both birth times were supplied, read the inter-chart house aspects. These describe which arenas of life are being activated by which of their planets in your chart, and vice versa. They are the texture of the day-to-day relationship — who triggers your work life, who triggers your home life, who triggers the version of you that comes out under stress. They are read by relationship coaches more than they are read by casual users, but they are in the report for any reader who wants them.

Common questions

Where to go from here