The chart records the zodiac positions of the Sun, Moon, and planets at the chosen moment. With an accurate time and birthplace, it also shows the Ascendant, Midheaven, chart angles, and twelve houses in relation to the local horizon.

The wheel is a compact diagram of those calculations. Planet symbols are placed around the zodiac. House cusps divide the interior into twelve areas. Lines across the center usually show selected aspects, which are angular relationships between planets or points.

The chart does not explain itself. Interpretation begins by identifying the most reliable and repeated patterns rather than collecting isolated keywords for every symbol.

Before reading the chart, confirm the birth date, local birth time, birthplace, and time-zone conversion. A calculation uses the birth moment in universal time along with the location’s latitude and longitude. A wrong time zone or daylight-saving assumption can move the angles and houses even when the typed clock time looks correct.

Also check the chart settings. Most Western astrology charts use the tropical zodiac, but a calculator may offer sidereal options. House systems can also differ. If two chart wheels disagree, compare these settings and the entered birth data before interpreting either version.

The twelve zodiac signs form a 360-degree circle around the outside of the wheel. They usually run counterclockwise. Planet glyphs sit at their calculated degrees, and an R beside a planet often indicates apparent retrograde motion.

The Ascendant marks the eastern horizon and begins the first house in many common chart layouts. The Descendant sits opposite it. The Midheaven and Imum Coeli form the other main axis. The exact position and visual orientation can vary by software, so use the labels and degree table rather than relying only on where a symbol appears on the screen.

Aspect lines cross the interior of many chart wheels. Their colors are a design convention, not an astrological rule. Always check the chart’s key or aspect table to see which relationships the software is displaying.

These three layers answer different questions. Keeping their roles separate prevents a common beginner mistake: treating a sign, planet, and house as interchangeable labels.

Suppose Mercury is in Taurus in the seventh house and forms a square to Saturn. An interpretation would not stop at “Mercury in Taurus.” It would consider Mercury’s communication function, the sign’s style, the relationship area represented by the seventh house, and the pressure or structure suggested by the Saturn aspect. It would then look for similar themes elsewhere in the chart.

An aspect is measured by the angular distance between two positions. Common major aspects include the conjunction at approximately 0 degrees, opposition at 180 degrees, square at 90 degrees, trine at 120 degrees, and sextile at 60 degrees.

The orb shows how far the aspect is from mathematical exactness. If two planets are 88 degrees apart, their square has an orb of 2 degrees. Astrologers and software use different orb limits, so an aspect may appear in one chart table and not another.

Aspects should be read as relationships between specific functions. A square is not automatically bad, and a trine is not automatically good. The planets involved, the orb, repeated patterns, and the person’s lived context all matter.

The Sun, Moon, and Ascendant are often called the “big three” because they provide a practical entrance into the chart. The Sun is commonly read in relation to identity and direction. The Moon is associated with emotional response and security. The Ascendant describes the eastern horizon at the birth moment and helps organize the houses.

Next, identify the ruler of the Ascendant’s sign, sometimes called the chart ruler. Note its sign, house, and major aspects. Planets placed close to the Ascendant, Midheaven, Descendant, or Imum Coeli may also deserve early attention because of their angular position.

If the birth time is not reliable, do not invent an Ascendant. Begin with the planetary positions that remain supported and state the limitation.

Online descriptions often make each placement sound independent. A real chart is a connected system. A planet may be strengthened, redirected, or complicated by its aspects. Several placements may repeat the same theme, while another apparent contradiction may describe how the person behaves differently under different conditions.

Look for repetition by element, modality, house area, planetary emphasis, and aspect pattern. Then ask which observations are most relevant to the question being considered. A relationship question will direct attention differently from a question about work, family, or a major transition.

1. Verify the birth data, time zone, zodiac, and house settings.
2. List the Sun, Moon, Ascendant, and chart ruler.
3. Note planets near the four chart angles.
4. Identify the tightest major aspects and any repeated aspect pattern.
5. Look for repeated emphasis by sign, element, modality, or house.
6. Combine planet, sign, house, and aspect before drawing a conclusion.
7. Relate the supported pattern to the actual question and context.

This order is not the only valid method. Its purpose is to keep the reading grounded in chart structure before moving into detailed interpretation.

Without an exact birth time, many planetary sign positions and aspects can still be available. Slower-moving planets change little during one day. The Moon moves more quickly and may need a range check.

The Ascendant, Midheaven, houses, and house-based statements should not be presented as confirmed without sufficient time information. A noon chart can be useful for checking planetary ranges, but noon is not a substitute for an unknown birth time. Read Why Birth Time Matters in Relationship Astrology for a fuller explanation.

Once two natal charts are calculated, they can be compared through synastry or used to calculate a composite chart.

If you plan to use a general AI tool for the next step, read Can ChatGPT Read Your Birth Chart Accurately? to understand which calculations and assumptions need to be checked first.

These references explain the structure of the chart wheel and the astronomical calculations behind planetary positions, houses, angles, and aspects.

• Introduction to AstrologyAstrodienst
• Horoscope Chart and Chart DrawingAstrodienst Astrowiki
• Birth Charts: Positions, Houses, and AspectsSwiss Ephemeris JS