Birth Chart Basics
What Is a Birth Chart?
A birth chart is a snapshot of the sky at your birth, and this walks through planet, sign, and house so the wheel stops feeling like homework.
⟶Free Birth Chart Calculator
Your natal chart is a map of the sky at the moment you were born: a wheel, every planet in its sign and house, and what each placement means. Enter your date, time and place.
What's in your chart
You get the chart wheel and every planet with its sign and house, plus the north and south nodes, Black Moon Lilith, the Midheaven, your chart ruler, a count of your elements and the Moon phase you were born under. Each one links to what it means. Chiron isn't included. The node is the true node and Lilith is the mean Black Moon Lilith, which can explain a small difference from another app.
How houses are counted
Houses use the whole sign system. Your rising sign is the entire 1st house, the next sign is the 2nd, and so on around the wheel. Many apps default to Placidus, so a planet can sit one house over there. Houses need your exact time and place, the same as the rising sign.
Where to start reading
Begin with the Big Three: Sun, Moon and rising. Then look at the element count and the chart ruler. A chart holds a lot, and it reads better a piece at a time.
Questions
Do I need my birth time?
A date and place get you the planets' signs, and the tool shows both signs if a planet changed signs that day. There's no rising sign and there are no houses without a time and place, and it never fills in noon for you.
Why is a planet in a different house on another app?
Other apps often default to Placidus houses, which divide the chart differently. This chart uses whole sign houses, so a planet can show one house over.
How accurate are the positions?
Positions come from Astronomy Engine, open-source astronomy software, and we checked them against Swiss Ephemeris, a standard reference, on 400 random charts from 1930 to 2035. Planets agreed to within about 20 arcseconds.
Is it free, and is my chart private?
It's free, with no sign-up or email. The chart is calculated in your browser and your birth details are never sent anywhere or placed in the page address.
Keep reading
Birth Chart Basics
How to Read a Birth Chart: Where to Start
Confused by your birth chart? Start with just three placements, Sun, Moon, and rising, and write one honest sentence about each before touching the rest.
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Houses
Whole Sign Houses vs. Placidus: Why Your Planets Change Houses Between Apps
Your planet didn't move between apps. The house lines did. Here's how whole sign houses and Placidus divide a chart, and how to check any app by hand.
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Birth Chart Basics
What You Can Learn Without a Birth Time
No birth time yet? Your Sun sign and most planets are still solid. This explains what stays certain and why your rising sign and houses have to wait.
⟶Planet positions from Astronomy Engine. Birthplaces from GeoNames (CC BY 4.0).