Birth Chart Calculator
Enter your birth date, time and place. You get the full natal chart wheel, every planet by sign, the houses and the aspects, in two zodiacs at once. Free, no name or email for the chart.
Free result. No name or email required.
Synthesis uses 13 unequal sign bands, including Ophiuchus. This is not the equal-sign Lahiri zodiac.
What a birth chart is
A birth chart, or natal chart, is a map of the sky at the moment and place you were born: where the Sun, Moon and planets stood against the zodiac, which sign was rising on the eastern horizon, and how those points relate to each other. Your Sun sign is one line of it.
Most calculators draw that map in one zodiac. This one draws it in two: the tropical zodiac used by Western astrology and the true sidereal zodiac measured against the constellations themselves, with Ophiuchus. When a planet lands in different signs in the two, that difference is information, not an error.
How to read the wheel
- 1Start with the big three. Sun (core drive), Moon (emotional reflexes) and the rising sign (how you meet the world). Together they explain most first impressions and most of what people mean by 'my sign'.
- 2Then the personal planets. Mercury is how you think and speak, Venus what you are drawn to, Mars how you pursue it. These change sign every few weeks, so they separate you from everyone born the same year.
- 3Look at houses for where, not how. The twelve houses are areas of life: identity, resources, communication, home, creativity, work, partnership and so on. A planet's house says where its energy shows up; the sign says how.
- 4Aspects are the conversations. Angles between planets: conjunctions blend, oppositions pull, squares create friction that has to be worked, trines flow. A chart with many hard aspects is not a bad chart; it is a busy one.
Common questions
What does a birth chart calculator need?
Your birth date, the time as exactly as possible, and the city. The time sets the rising sign and the houses, which move through all twelve signs in a day; the place sets the horizon. Without a time the chart still shows every planet's sign, with the rising sign and houses left out.
Is my birth chart different in the sidereal zodiac?
Often. The tropical zodiac is anchored to the seasons and the sidereal zodiac to the constellations; they have drifted roughly a full sign apart, and true sidereal also uses the constellations' real, unequal widths, with Ophiuchus. Most people have a different Sun sign in the two. The calculator shows both so you can see which one a given book or app is using.
What are the houses in a birth chart?
Twelve divisions of the sky starting from the eastern horizon at your birth, each standing for an area of life. This calculator uses Placidus houses for the tropical wheel, the most common system in Western astrology, and falls back to equal houses at extreme latitudes where Placidus breaks down.
Is the birth chart calculator free?
Yes. The wheel, the placements table and the aspects are free and need no signup. Saving the chart to your account and the written interpretation across five systems are the next step, shown after the result.
Why do different calculators give me different charts?
Usually one of four things: the zodiac (tropical or sidereal), the house system, a time-zone or daylight-saving error for historical births, or a rounded birth time near a sign boundary. This page states its zodiacs and house system so you can compare like with like.