Most relationship charts start with a philosophical problem: a relationship has no birth certificate. The composite chart solves it by averaging two charts point by point. The Davison chart, named after the English astrologer Ronald Davison who described it, solves it another way. It asks a simple question: if this relationship had been born, when and where would that have been?

Its answer is the moment exactly halfway between the two births, at the point exactly halfway between the two birthplaces. Then it casts an ordinary chart for that moment, over that place. Everything in it really happened. The planets stood in those degrees, over that spot, on that day.

How it is built

Two midpoints make a Davison chart.

The midpoint in time is the instant halfway between the two births. If one person was born at dawn on a spring day in 1990 and the other in the autumn of 1994, the Davison moment falls somewhere in 1992, at a precise minute.

The midpoint in space is the average of the two latitudes and the two longitudes, as Davison drew it and as most astrology software does, so the houses match a Davison cast elsewhere. One case is handled differently on our site: when the two birthplaces lie on either side of the 180th meridian, the longitudes are averaged the short way round. Someone born in Tokyo and someone born in Los Angeles meet in the Pacific between them, rather than somewhere on the other side of the world.

That point is often nowhere either person has been: the middle of an ocean, a desert, a country neither has visited. Our report names it, for example "in the North Atlantic", and tells you how many years and how many kilometres apart your births are. A pair born in two port cities may find their relationship was born at sea, which is interesting, and no reason to buy a boat. The midpoint is a construction, not a destination. Its job is to fix the houses, and it fixes them consistently for the pair.

Davison or composite?

The two relationship charts disagree about a couple, and they are meant to.

A composite takes the midpoint of each pair of planets: your Sun and theirs make the composite Sun. It is a useful abstraction, but no sky ever looked like it. It has no moment, so it cannot really be transited, progressed or given a return, and its houses are equal divisions from a midpoint Ascendant.

A Davison is a date and a place, so all of that works on it. It has a real Ascendant and Midheaven, and twelve houses from a real horizon. And because it is a real sky, its planets stand where the sky put them, not halfway between two positions. An average of two positions is not the position at the average moment, so the two charts can put a planet in different signs.

Here is the simplest example. The Moon moves fast, about thirteen degrees a day. In a composite, the Moon is the midpoint of the two natal Moons. In a Davison, it is wherever the Moon actually was at the midpoint moment, which can be somewhere else entirely. Neither is wrong. The composite is the relationship as an idea; the Davison is the relationship as an event in the world. Where they agree, the case is stronger. Where they differ, the composite is usually nearer to the feel of the thing, and the Davison nearer to its timing.

How to read it

Read the Davison as a chart in its own right first, the way you would read a birth chart.

Its Sun says what the relationship is for. Its Moon says how it feels from inside. Its Ascendant says how it appears to everyone else, which may surprise both partners. A Davison with Leo rising is a pair other people notice when they walk into a room, even if both partners would rather sit quietly near the door.

Then read the houses, which are the real reason to cast a Davison. They are the areas of life the relationship itself occupies. A Davison with several planets in the fourth house is a relationship that lives at home: the shared kitchen, the family, the question of which chair belongs to whom. Planets in the tenth put the relationship in public: a pair who work together, or who are known as a pair. Planets in the ninth suggest travel, study and long conversations about meaning, possibly while lost.

Then read the aspects inside the chart. They are not aspects between your two charts; they belong to the relationship. A Davison Venus square Saturn describes an affection that keeps meeting a limit. A Davison Mars trine Jupiter is a pair who start projects with enthusiasm, and, at least some of the time, finish them.

Only then compare it with the two birth charts it came from.

What our report shows

Our Davison report gives you the moment and the place between you, the chart wheel, and a table of the chart's planets with their signs and, when both birth times are known, their houses. Then come the twelve houses of the chart, with where each begins and which planets stand inside it. Then the aspects the chart makes, closest first: the major aspects, and a few of the finer ones, such as the quincunx, at tight orbs.

A button asks the AI astrologer for a reading of the whole chart. It is written in a few seconds, and once written it is kept for you and opens right away the next time. The page ends with a short section on when to use the Davison and when the composite.

Birth times

Both birth times matter, for the same reason as in any chart. The planets are fine without them; the houses and angles are not. If one time is unknown, our report casts the chart for noon on that side, and leaves out the Ascendant, the Midheaven and the houses rather than printing ones it does not believe. You still get a readable Davison of planets and aspects.

Note that an error in either birth time moves the midpoint by half of it. Half an hour of error still moves the Davison Ascendant by several degrees, so the more accurate both times are, the better.

A description, not a grade

A Davison with hard aspects is not a verdict, and an easy one is not a guarantee. Both describe what the pair will keep meeting. And since a Davison has a real date, it can be followed through time: the planets moving overhead make transits to it, just as they do to a birth chart.

When you are ready, cast the Davison chart for two people here, and then follow what the sky is doing to it, day by day or month by month.

Frequently asked questions

What is a Davison chart?
A real chart cast for the midpoint in time between two births and the midpoint in space between the two birthplaces. Because that moment and that place existed, the Davison is a chart of something, not an average of two charts.

How is it different from a composite chart?
A composite averages the two charts point by point and has no moment, so it cannot really be progressed or transited, and its houses are equal slices from a midpoint Ascendant. The Davison is a date and a place, so it has real houses and can be followed through time. Most astrologers read both and take seriously where they agree.

Do we both need a known birth time?
For the planets and their aspects, no. For the Ascendant and the houses, yes, and those carry much of how a relationship is actually lived. With an unknown time, read the aspects and treat the houses as missing.

The midpoint place is in the middle of the sea. Is that a problem?
No. The midpoint is a construction rather than a place anyone is meant to go. Its job is to fix the houses of the chart, and it does that whether or not anybody could stand there.

Can a Davison chart be transited?
Yes, and that is the practical reason to prefer it for timing. It has a real date and a real horizon, so transits to it mean something in the ordinary way. Our site has Davison transits for a single day and for a whole month.