Free calculator
Birth chart calculator
Enter your birth date, time and place to see your full natal chart: planets, Ascendant, houses and aspects. Daylight saving and historical time zones are applied automatically.
How this birth chart is calculated
We convert your local birth time to Universal Time using the IANA time zone database, including historical daylight-saving rules. Planet positions are apparent geocentric longitudes on the tropical zodiac from Astronomy Engine. The Ascendant and Midheaven come from local apparent sidereal time and the true obliquity of the ecliptic; Placidus cusps are found by trisecting each cusp's semi-arc. Read the full methodology and accuracy checks.
Frequently asked questions
What is a birth chart?
A birth (natal) chart is a map of where the Sun, Moon and planets were along the zodiac at the moment and place you were born, together with the Ascendant, Midheaven and twelve houses calculated from the local horizon.
Do I need my exact birth time?
For planet signs, usually not: only the Moon moves fast enough to change signs within a day. The Ascendant, Midheaven and houses need a time accurate to a few minutes, because the Ascendant moves about one degree every four minutes.
Which house system do you use?
Placidus by default, the most common system in modern Western astrology. You can switch to Whole Sign houses. Above about 66° latitude Placidus is undefined and we use Whole Sign automatically.
How accurate are the planet positions?
Within about 20 arcseconds of NASA JPL Horizons in our published comparison; see the methodology page. Zodiac signs are 30° wide, so this is far more precise than astrology needs.
Do you store my birth details?
No. Your chart is calculated when you submit the form and is not saved or logged.
Astrology is a symbolic and cultural tradition. The planetary positions on this site are calculated with astronomical accuracy; the interpretations describe what astrologers associate with them and are not scientifically validated predictions about personality, relationships or the future.