Planets
What is acting
Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, plus calculated points used by the chart.
Free natal chart calculator
Free birth chart calculator: planets, houses and aspects
Enter your birth date, recorded local time, and birthplace to calculate your natal chart with exact planetary degrees, Sun, Moon and Rising signs, Placidus houses, chart angles, and major aspects.
- Swiss Ephemeris positions
- Free complete result
- Private expiring chart link
- Method and limits stated
Calculation settingsTropical zodiac · Placidus houses · historical timezone
The direct answer
What is a birth chart?
A birth chart—also called a natal chart—is a map of the zodiac for the date, local time, and place of birth. It shows which signs the planets occupied, where those planets fall in the twelve houses, and the angular relationships between them. The chart is a symbolic framework for reflection, not a scientific diagnosis or a promise about events.
What your result includes
One chart, four layers of information.
A useful natal chart separates the astronomical calculation from the interpretation. Zodiaro first resolves the positions and geometry, then explains how astrologers commonly read each layer.
Zodiac signs
How it acts
Each placement is reported by sign and exact degree, including direct or retrograde motion where applicable.
Houses and angles
Where it acts
The Ascendant, Midheaven, twelve Placidus house cusps, and each planet’s house are calculated when a recorded birth time is available.
Aspects
How the parts relate
Conjunctions, oppositions, squares, trines and sextiles describe the geometry between chart factors and the orb from exactness.
How the calculation works
From local birth record to a precise sky map.
The calculator does not assign placements from a generic date table. It resolves the birth moment, coordinates, and astronomical longitudes before it draws the chart.
Read the full calculation methodology- 01
Resolve the place and timezone
The chosen birthplace supplies latitude, longitude, and an IANA timezone. The recorded local time is converted to UTC with the applicable historical offset.
- 02
Calculate planetary positions
Swiss Ephemeris calculates geocentric tropical longitudes and speed for the birth moment instead of relying on a simplified annual lookup.
- 03
Build the local house wheel
When time is known, the location and moment determine the Ascendant, Midheaven, and twelve Placidus cusps.
- 04
Measure chart geometry
Angular distances are evaluated for major aspects, and the result preserves the numerical placement behind each interpretation.
Unknown birth time
A partial chart is better than a confident guess.
If the time is unknown, Zodiaro uses a noon reference for planetary positions and labels the limitation. It does not invent a Rising sign or house wheel. The Moon is also flagged when the day contains a possible sign change.
With a recorded time
You receive the Ascendant, Midheaven, houses, angular placements, and a time-sensitivity view around the recorded moment.
Without a recorded time
You still receive a useful planetary map, but the Rising sign and houses are withheld because they cannot be recovered from a date alone.
How to read a natal chart
Read in layers, not isolated labels.
The most useful interpretation asks the same four questions in a repeatable order.
| Layer | Question | Example | Avoid this shortcut |
|---|---|---|---|
| Planet | Which function is involved? | Venus: relating, values and pleasure | Treating one planet as the whole personality |
| Sign | What style does it use? | Venus in Virgo: selective, attentive, practical | Reducing a sign to “good” or “bad” |
| House | Where does it become visible? | Venus in the 10th: values and alliances shape public work | Using houses without a reliable birth time |
| Aspect | What modifies or challenges it? | Venus square Saturn: closeness and caution must negotiate | Reading an aspect without its orb and wider chart |
Questions, answered
Birth chart calculator FAQ
What is a birth chart?
A birth chart, also called a natal chart, is a map of the tropical zodiac for a specific date, local time, and birthplace. It records planetary signs and degrees, chart angles, houses, and the angular relationships called aspects.
What information is needed for an accurate natal chart?
Use your birth date, the local time recorded at birth, and birthplace. The date locates the planets; the recorded time and location are required for an exact Ascendant, Midheaven, and house cusps.
Can I calculate a birth chart without a birth time?
Yes, but it is a partial chart. Zodiaro uses a noon reference for planetary positions and intentionally withholds the Rising sign and houses. The Moon can also require a time check when it changed signs on that date.
Which zodiac and house system does Zodiaro use?
Zodiaro uses the tropical zodiac and Placidus houses. The result states these settings so a comparison with another calculator uses the same assumptions.
Why can two birth chart calculators show different results?
First compare the birth time, AM or PM, selected city, historical timezone, tropical or sidereal zodiac, house system, and node settings. Different inputs or conventions can produce different angles, houses, and sometimes a boundary placement.
What is the difference between signs, houses, and aspects?
A planet names the function, its sign describes how that function operates, its house shows where it is emphasized, and its aspects describe how it cooperates or conflicts with other chart factors.
Is the Zodiaro birth chart calculator free?
Yes. The public calculator creates a free chart with planetary positions, houses when time is known, major aspects, and a printable visual summary. No payment details are required.
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Astrology is offered as a reflective and educational practice. It is not medical, legal, financial, or mental-health advice and does not guarantee outcomes.