Birth Chart (Natal Chart)

What is a birth chart?

A birth chart, also called a natal chart, is a map of the sky calculated for the exact moment and place of your birth, showing where the Sun, the Moon and the planets stood in the zodiac as seen from that spot on Earth. It is drawn as a wheel: the twelve signs around the outside, the twelve houses dividing the wheel like slices, the planets placed inside, and lines between them for the aspects.

Your Sun sign is one detail of this map. The chart as a whole holds every layer of the personality at once, which is why astrologers read it, rather than the Sun sign alone, when they describe a person. Its building blocks are:

Element	What it is	What it tells
Planets	the Sun, the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto	what is acting: identity, feeling, thought, love, drive, growth, structure and the rest
Signs	the twelve 30° sections of the zodiac	how each planet acts: its style
Houses	twelve sectors set by birth time and place	where in life it acts: home, work, partners and so on
Aspects	angles between planets: 0°, 60°, 90°, 120°, 180°	how planets talk to each other: easily or with tension
Angles	ascendant, descendant, Midheaven (MC), IC	the horizon and meridian lines that anchor the houses

Many charts also include calculated points such as the lunar nodes and additional bodies such as Chiron, whose position is plotted alongside the planets. Together these elements describe a single, unrepeatable moment: even twins born a few minutes apart can have slightly different charts.

From Babylonian tablets to the natal chart

The oldest known personal horoscopes are Babylonian cuneiform tablets from the late fifth century BC, which record the positions of the Moon and planets on the day a child was born. In Hellenistic Egypt, from around the second century BC, Greek-speaking astrologers combined that Babylonian sky-watching with Egyptian timekeeping and Greek philosophy, and the chart we know took shape: twelve signs, a rising degree, places that became the houses, and aspects measured between planets.

The word horoscope comes from that tradition. The Greek horoskopos, “hour-marker”, was the rising degree, and the name of that one point came to mean the whole chart. Medieval Arabic and Persian astrologers refined the techniques, and Renaissance Europe inherited them.

For centuries, calculating a chart meant tables, arithmetic and hours of work. In the twentieth century two things changed: psychological astrology began reading the chart as a portrait of the inner life rather than a forecast, and later computers made a precise chart available in seconds. The map is the same; what astrologers look for in it has widened.

How to start reading a natal chart

Begin with the big three. The Sun, the Moon and the rising sign give the outline: core identity, emotional needs and the approach to life. Everything else fills in this sketch.

Find the chart ruler. Whichever planet rules your rising sign is the chart ruler. Its sign and house show the area of life where your whole approach is lived out.

Look at where the planets gather. Count planets by house and by element. Several planets in one house, or a stellium, point to an area of life that takes a lot of energy; no planets in earth puts the chart’s emphasis in the other elements. Use that balance to ask how practical routines, resources and stability enter the question.

Read the tight aspects. Give close attention to contacts with small orbs, particularly those involving the Sun, Moon or personal planets. A Sun–Saturn square or Moon–Venus trine adds a relationship between themes already placed in signs and houses. Use both house placements to locate where that tension or ease enters the question.

What it does not do. A birth chart does not decide events, health, money or the people you will meet. It describes tendencies and tensions, and many of the most interesting parts of a chart are the ones a person learns to use well over time.

Enter your birth date, time and place in the Larisa app’s Birth Chart and it returns the planets’ longitudes, the rising sign, the Placidus houses and the major aspects. Leave the time blank and the app takes about 12:00 noon so it can still show a result; the planets stay largely right, while the rising sign, the houses and the MC are then approximate.

Example: reading one chart in four steps

Take one chart: Sun in Cancer in the tenth house, Moon at 10° Aquarius in the fifth, Libra rising, and Venus at 10° Leo in the eleventh.

Step one, the big three. A caring, protective core (Cancer Sun), a need for independence and space in feelings (Aquarius Moon) and a courteous, diplomatic first impression (Libra rising). People meet someone pleasant and easy to talk to; those close to them find feelings that are cooler and more independent than the manner suggests.

Step two, the chart ruler. Libra rising is ruled by Venus. Venus in Leo in the eleventh house sends the whole approach to life into friendships, groups and shared projects, lived warmly and generously.

Step three, the emphasis. The Sun sits at the top of the chart, in the house of career and public life. This person’s sense of self is closely tied to their role in the world, and caring for others may well become their work.

Step four, the tension. The Moon in Aquarius opposes Venus in Leo. The need for emotional freedom pulls against the wish to be warmly seen and appreciated by friends. The chart does not say which wins; it shows the balance this person keeps working out between belonging and room to breathe.

These four steps give an outline of the chart. Deepen each one with the other house placements, the remaining planets and the degrees and orbs of their aspects.