How to Read a Birth Chart
A birth chart looks complicated at first, a wheel full of glyphs and crossing lines, but it's built from just four layers, stacked on top of each other. Once you can separate them, the whole thing stops being noise and starts being readable.
1. Planets: what
Each planet represents a distinct drive or function of the psyche, the Sun is identity, the Moon is emotional instinct, Mercury is communication, and so on. Think of the planets as the cast of characters in the chart. Nothing about a planet's meaning changes from person to person; what changes is where each one was standing at the moment you were born.
Read the full lesson on the planets.
2. Signs: how
Every planet sits in one of the twelve zodiac signs, and the sign describes the style that planet expresses itself in. Mars in Aries pursues what it wants directly and impatiently; Mars in Capricorn pursues the same underlying drive patiently and strategically. Same planet, same basic drive, different manner.
Read the full lesson on the zodiac signs.
3. Houses: where
The chart is also divided into twelve houses, each tied to an area of life, identity, home, career, relationships, and so on. A planet's house tells you where in life its energy is most concentrated. Venus in the 10th house brings Venus's themes (attraction, values, charm) into career and public reputation; Venus in the 4th brings the same themes home, into family life.
Read the full lesson on the twelve houses.
4. Aspects: how the characters interact
Finally, planets form geometric angles with each other, aspects, which describe how different parts of the personality cooperate or conflict. A trine (120°) is generally easy, flowing cooperation. A square (90°) is friction that usually forces growth. A conjunction (0°) fuses two planets' energy into one blended force.
Read the full lesson on aspects.
Putting it together
A full sentence about a single placement reads like: "[Planet] in [Sign] in the [House] house, [aspect] to [another Planet]." For example: "Venus in Capricorn in the 10th house, square Mars" describes someone whose approach to love and value (Venus) is disciplined and reserved (Capricorn), expressed most visibly through career and reputation (10th house), and in ongoing creative tension with their drive and assertiveness (square Mars).
That's the whole method. Every placement in your own chart is built from exactly this same four-layer structure. Use the birth chart calculator to see all of yours at once, then come back to the lessons linked above whenever you want to go deeper on any one layer.