How to read a birth chart, beginning with three positions
A birth chart is a drawing of the sky over a single place at a single instant, flattened into a circle. Reading one begins with the notation rather than with the meanings, because every mark on the wheel resolves to the same three things: a body, a sign and a degree.
The wheel is one horizon, not a map of the solar system
The circle is the ecliptic: the path the sun traces through the year, closed into 360° and cut into twelve arcs of 30°. Degrees run anticlockwise. By long convention the ascendant is drawn at the left-hand edge, so the horizon of the birthplace lies across the middle of the drawing, sky above and ground below.
That layout carries information before anything is interpreted. Whatever sits in the upper half stood above the horizon at that instant; whatever sits in the lower half was underfoot, on the far side of the earth. A midnight birth puts the sun at the bottom of the wheel and a noon birth near the top, which is often how a mistranscribed hour gives itself away.
Distance is gone from the drawing, depth is gone, and the earth occupies the centre because the wheel is a record made from the ground looking outward. It is a register of directions taken from one doorstep, not a model of the solar system.
A position is a sign, a degree and a minute
Positions are written 23°14′ Taurus and read as twenty-three degrees and fourteen minutes of Taurus. The minute is an arcminute, a sixtieth of a degree, from the sexagesimal arithmetic astronomy inherited from Babylon and never found a reason to abandon. It has nothing to do with the minute on a clock.
The same figure can be written two ways. Ecliptic longitude counts from 0° to 360° from the vernal point; divided by 30°, the quotient names the sign and the remainder gives the degree within it. So 53°14′ of longitude and 23°14′ Taurus are the same place, and every position printed on this site can be read either way.
How many of those digits mean anything depends on the body, and the tolerances are listed at /method. The lunar one is the instructive case: about ±0.2° is roughly 12′, so a moon printed at 23°14′ is honestly somewhere between 23°02′ and 23°26′. The habit worth forming is to read a degree as a distance from the nearest boundary rather than as an exact quantity, since that distance is what decides whether the tolerance matters at all.
What houses, aspects and the other planets are for
Houses are a second division of the same circle. The zodiac is cut from the vernal point by the seasons; houses are cut from the ascendant by the local horizon and meridian, into twelve sectors traditionally assigned to departments of a life: the body, resources, kin, home, work. They place a general position in a particular corner of living.
The difficulty is that there is no single way to cut them. Whole sign, Placidus, Koch and Regiomontanus produce different cusps from the same birth data, so one planet falls in the ninth house by one method and the tenth by another, and the unequal systems misbehave at high latitudes. That choice belongs to a school, not to the astronomy.
Aspects are the angular distances between two positions, 0°, 60°, 90°, 120° and 180°, each allowed an orb of a few degrees on either side, and read as how two parts of a chart bear on one another. The other planets widen the vocabulary and are governed by their speeds: Mercury never strays more than about 28° from the sun and Venus about 47°, while Pluto can spend a decade in one sign and three decades in another. The outermost bodies therefore describe a school year rather than a person.
None of the three appears on this site, and the reason is auditability rather than difficulty. A position with a stated error can be laid beside another ephemeris and checked; a house cusp cannot be checked at all until the system in use has been settled, and an aspect inherits the uncertainty of both positions it joins. Hence the boundary at /method: the sun, the moon and the ascendant, and nothing further.
Three positions, and two things to do with them
The three can be collected in a few minutes and cost nothing: the sun sign from the date at /zodiac-dates, the moon at /moon-sign, the ascendant at /rising-sign. Each returns a degree alongside the sign, in the notation above, arcminute included. What the three describe, and why they so often disagree, is the subject of /blog/three-placements.
One seam runs through any chart, drawn here or elsewhere. The positions are computed; the sentences beneath them are inherited, and on this site written by Claude, an AI, working in the astrological tradition. A reader who keeps those two halves apart will not mistake a precise number for a true paragraph.
Two things can then be done with them. The first is to note how far each stands from the nearest boundary, since a position at 0°40′ or 29°30′ is worth re-checking against the recorded hour. The second is to find the pair that disagrees, which is where a chart stops describing a category and starts describing a person. /chart is the paid version that writes the three up together, US$19.