Free birth chart
Your Free Birth Chart
Calculated, Not Guessed
Professional-grade ephemeris, cross-verified against Swiss Ephemeris to within one arc-minute. Whole-sign houses — the same standards behind every Astrara reading.
What a birth chart actually is
A birth chart is a map of the sky from one place, at one moment: yours. It records where the Sun, Moon and planets stood relative to the horizon at your birth, and how far apart they were from each other. Nothing mystical happens in the calculation itself — it is astronomy, worked backwards to the minute you arrived. What astrology adds is a language for reading that map, built up over a couple of thousand years of people watching the same sky.
Because the Earth turns a full 360° every day, the chart changes fast. The Moon moves about half a degree an hour and the Ascendant moves a whole degree every four minutes. Two people born in the same city on the same day, six hours apart, share a Sun sign and almost nothing else. That is why a birth time matters so much more than most people expect.
The Big Three, and why they are the three
Your Sun sign is the one you already know: the core of what you are reaching towards, the thing you are practising being. Your Moon sign is the private half — how you settle yourself, what you need in order to feel safe, the reactions that arrive before you have chosen them. Your Rising sign, or Ascendant, is the sign that was climbing over the eastern horizon as you were born: the manner you meet the world in, and the doorway everything else in the chart is arranged around.
Together they explain why two people with the same Sun sign can feel nothing alike. Sun tells you the direction. Moon tells you the weather inside. Rising tells you what the room sees first.
Why whole-sign houses
The twelve houses are areas of life — work, home, relationship, health. Systems differ in where they draw the lines between them. This calculator uses whole sign: your Rising sign becomes the whole of the 1st house, the next sign the whole of the 2nd, and so on around. It is the oldest approach in Hellenistic astrology, and it is what every Astrara reading is built on, so the chart you get here will not contradict a reading you buy later.
It is also the honest choice at high latitudes. Quadrant systems like Placidus divide the day by time rather than by sign, and above roughly 60° north or south they start producing houses that stretch across three signs or collapse to nothing. Whole sign simply does not have that failure mode — a chart cast in Tromsø is as coherent as one cast in Lisbon.
Why the accuracy of the ephemeris matters
Plenty of free calculators use rough polynomial approximations that drift by degrees over a century, which is enough to put a planet in the wrong sign entirely for someone born in the 1930s. The positions here are computed with full VSOP87/ELP planetary theory, and Chiron is sampled from NASA JPL Horizons.
That is a claim worth checking rather than taking on trust, so we check it. Every body in the chart is batch-compared against Swiss Ephemeris — the reference the professional field uses, and the engine behind Astrara’s own paid readings — across thousands of instants spanning the whole 1900–2080 range this calculator accepts, with the Ascendant tested at twelve latitudes from Patagonia to the Arctic. Everything agrees to within one arc-minute; most of it to a hundredth of one. The full result, including the deviation for each body, is published in the repository.
The subtler failure is the timezone. Converting a local birth time to universal time means knowing what the clocks actually said in that country on that date — not what they say now. Lithuania in June 1981 ran on UTC+4, Portugal held permanent CET from 1966 to 1976, and wartime Britain ran double summer time. Assume today’s rules and you can shift an Ascendant by a whole sign. Every conversion here goes through the IANA timezone database, which encodes all of it.
Questions
Is it really free?
Yes — the whole chart, with no account and no email required to see it. You only give an email address if you want the chart saved and sent to you. Astrara makes its money from the personalised readings, not from the calculator.
What if I don’t know my birth time?
The calculator still works. It computes for 12:00 at your birthplace and shows your Sun and planets as normal, but leaves out the Ascendant and the houses rather than guessing them, because those change every few minutes. If the Moon changed sign on your birth date, you are told the exact time it switched so you know which of the two applies.
What house system do you use?
Whole sign houses. Your Ascendant’s sign becomes the entire 1st house, the next sign the 2nd, and so on. It is the oldest house system in Western astrology, it is what every Astrara reading uses, and unlike Placidus it stays coherent at far northern and southern latitudes instead of producing distorted or impossible houses.
How accurate is it?
Positions are computed with a professional astronomical engine (VSOP87-class), Chiron comes from NASA JPL Horizons data, and the whole system is batch-verified against Swiss Ephemeris across the full 1900–2080 range it accepts — the same verification discipline behind every paid Astrara reading. Every body agrees to within one arc-minute. The part most calculators get wrong is the timezone: birth times are converted using the IANA timezone database, so historical offsets — wartime clocks, Soviet-era time, Portugal’s permanent CET years — resolve correctly instead of being assumed from today’s rules.