What is a birth chart (natal chart)?
Your birth chart is a snapshot of the sky at the moment you came into the world. It shows the exact positions of the Sun, Moon, and planets as seen from your birthplace in that second. Those positions never repeat exactly again — which is why the chart is like your fingerprint on the sky. Astrology reads it as a map of possibilities: not a fixed table of fate, but a map of your tendencies, needs, and tensions.
Cosmir draws this chart not by estimation but with real celestial mechanics. For the moment you enter, planetary positions are computed with the Swiss Ephemeris and houses with the Placidus system. Every degree you see corresponds to a real celestial event.
What do you look at in a birth chart?
At first glance the chart looks crowded, but once you recognize a few cornerstones it becomes readable:
- Sun, Moon, and Rising — the three cornerstones of the chart. The Sun is your essence and life direction, the Moon your emotional inner world, and the Rising your outward manner and the point where the chart begins. You can explore these separately on the rising sign and moon sign pages.
- Planets — Mercury (mind), Venus (love and values), Mars (desire and action), and the rest; each sits in a sign and a house.
- Houses — the sky divided into 12 areas of life: relationships, career, money, home, learning… Which planet is in which house tells you where that energy operates in your life.
- Aspects— the geometric relationships between planets. Trine and sextile describe flow; square and opposition describe tension. A challenging aspect doesn’t mean “bad”; it’s often where growth comes from.
Why is birth time so important?
Your rising sign and your entire house system depend on the angle at which the sky rises over the horizon, and that angle shifts by one degree every four minutes. So even a few minutes’ difference can change your rising and houses. If you know your time, your chart gains a skeleton; if you don’t, it starts with your Sun and Moon signs, and you can refine the time later together in the app.
Why is Cosmir’s calculation accurate?
Many calculators online use simplified tables. Cosmir computes planetary positions with the Swiss Ephemeris, based on NASA/JPL data, and houses with the astrologers’ standard, Placidus. On your result page you see the raw degrees, retrograde motion, and exact house cusps as they are — nothing is hidden.
When you’re ready, fill in the form above — your chart will be in front of you in seconds. If you want a deeper reading, the AI astrologer in the app turns your whole chart into a conversation.