Free birth chart
Your natal chart
Every planet, sign and house in one wheel, each explained in plain English.
Common questions
What is a birth chart?
A birth chart, or natal chart, is a map of where every planet sat in the sky at the exact moment and place you were born. It shows your Sun, Moon and Rising signs plus seven more planets, each in a sign and a house. Together they describe your personality, needs and instincts far more precisely than a sun sign alone.
What do I need to calculate my birth chart?
Your birth date, your birth city and ideally your exact birth time. The time matters because your Rising sign and houses shift roughly every two hours. If you do not know your time, you still get your Sun, Moon and every planet sign.
Is this birth chart calculator really free?
Yes. Theia Sky computes your full chart with precision astronomy directly in your browser, free and with no account needed. Nothing is stored unless you choose to save your chart on your device.
How accurate is the chart?
Planet positions are calculated with the same astronomical models used by observatories, accurate to about one arcminute. That is far finer than any chart wheel can display.