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A guide for beginners, step by step

How to calculate and read your own cosmogram

An online calculator can create a date-based cosmogram quickly. The next step is understanding the wheel and its symbols. This guide takes you from entering a date to a connected interpretation, with five reading steps, an aspect table and a worked example.

Create a cosmogram online
Calculating a cosmogram online: a hand enters a birth date into a glowing star-themed interface

What you will need

Your date of birth is the starting point. A time gives more precise positions, especially for the Moon; without it, a midday calculation is an estimate. A birthplace is needed for a full chart with houses. We explain these differences in “What is a cosmogram?”.

Five steps for reading the chart

Create the chart. Open the calculatorand enter your date and, if known, time. The server calculates the positions of ten celestial bodies from astronomical ephemerides and draws the signs, planet markers and aspect lines.
Begin with the Sun and Moon. The Sun symbolises identity and motivation, while the Moon represents emotional needs and safety in astrological interpretation. Different elements can suggest contrasting themes to explore, without determining your personality.
Explore the personal planets. Mercury is associated with thinking and speech, Venus with love and values, and Mars with action and anger. Consider which descriptions resonate and which do not.
Look at the aspect pattern. Lines within the wheel connect the symbols. Gold lines mark traditionally harmonious aspects; reddish dashed lines mark tension. A planet with many connections can provide a useful focus for the reading.
Bring the themes together. A connected reading considers how motivations, feelings, communication, strengths and challenges interact. Try describing the overall picture in one paragraph rather than listing isolated placements.

Aspects: five angles to recognise

An aspect is an angle between two planets. Astrologers allow a margin called an orb, so a position close to 90 degrees may count as a square. Here are the main aspects.

Aspects in a cosmogram: a harmonious gold connection and a challenging red connection between planets
AspectAngleThemeTraditional interpretation
Conjunction0°combinationThe planets' themes are read together and can be difficult to separate.
Sextile60°harmonyAn opportunity for cooperation or support that develops through use.
Square90°tensionContrasting needs or challenges that invite effort and development.
Trine120°harmonyEase or a familiar strength that may be taken for granted.
Opposition180°polarityA pull between contrasting themes, inviting balance.
A useful exercise is to compare challenging and harmonious aspects. The former offer themes of tension; the latter, ease or support. Neither determines the quality of a person's life.

A worked example: connecting the whole chart

Take 6 May 2002 as an example and follow the reading steps.

An example cosmogram with a stellium: several planets in the same sign on a golden wheel

The example chart shows: Sun in Taurus, Moon in Pisces, and Mercury, Venus, Mars and Saturn in Gemini. Astrologers call a grouping of several planets a stellium.

The starting points. Taurus Sun is traditionally associated with steadiness, comfort and reliability. Pisces Moon adds themes of sensitivity and imagination: a symbolic contrast between a practical outer approach and a receptive inner experience.

The Gemini stellium. Four planets in the sign emphasise themes of communication, information and curiosity. A reading might connect this with quick thinking, lively conversation and attraction through words. Saturn adds a theme of restraint or an inner editor that checks what is said.

The connected interpretation. The contrast between steadiness and curiosity suggests a wish for both security and variety. As a reflective example, this might prompt someone to consider work with a reliable foundation and changing tasks, such as a project involving plenty of communication.

These steps show how astrological symbols can be assembled into an interpretation. Create your own chart in the calculatorand move over a planet to see its position label.

Common beginner mistakes

Reading placements as an isolated list. Try this: look for connections. Venus in Gemini gains more context when you also consider its aspects.
Being frightened by a square. Try this: treat it as a theme to explore. A challenging aspect is not a prediction of failure or harm.
Assuming the Moon's sign is certain without a birth time. Try this: keep both possibilities open if the Moon changes signs that day. A description that resonates cannot establish the correct position.
Judging a person from their Sun sign alone. Try this: remember that a Sun sign is only one part of an astrological chart, and the chart itself does not define a person.
A woman studying a golden sky chart by candlelight
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Explore these ideas with your own birth date

An interactive wheel with ten calculated celestial positions, aspect lines and interpretations. You can also explore a different symbolic approach with the Destiny Matrix.

Create a cosmogram Calculate my Destiny Matrix

Frequently asked questions

How can I calculate a cosmogram for free?
Enter your date of birth in Cosmogramma's calculator: calculated planetary positions and interpretations, with no registration required.
I do not know my birth time. What should I do?
Use a date-based chart and retain the uncertainty, particularly for the Moon and any body near a sign boundary. Reading a description cannot determine which position is correct.
Where should I begin reading?
Start with the Sun and Moon, then look at a planet with many aspects as another focus for interpretation.
What does R beside a planet mean?
It marks apparent retrograde motion. Astrologers associate it with a more inward expression of a planet's themes; it is not a defect.

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