Birth chart calculator
Enter your date, time and city of birth and see the whole chart: where each planet stood, which houses they fall in and how they connect. It’s free, and nothing is saved to an account.
- Ten planetsSun, Moon, Mercury to Pluto: sign, degree and minute, and whether the planet was retrograde.
- Rising & MidheavenThe Ascendant and MC for your birth minute and place.
- Twelve housesPlacidus cusps, with whole-sign houses where Placidus breaks down (above the polar circles).
- AspectsConjunctions, sextiles, squares, trines and oppositions, tightest first, with their orbs.
How it’s calculated
Positions come from our own ephemeris code, built on the open-source astronomy-engine library. We test it against Swiss Ephemeris, the reference most astrology software uses, and the planets, Ascendant and Midheaven agree with it to within one arcminute.
Your local birth time is converted to UTC with the IANA time-zone history for the city you pick. That history includes old daylight-saving rules and zone changes, so a 1970s birth in Kyiv or a 1940s birth in London is converted with the clocks that were actually in use.
The zodiac is tropical, the houses are Placidus. The chart wheel and tables show exactly what was calculated; nothing is estimated from your Sun sign.
Asked often
Is the birth chart calculator really free?
Yes. The chart, the wheel, the planet table, houses and aspects cost nothing and need no account or card. We sell optional books and readings written from the chart; you never have to buy one to see it.
How accurate is it?
The planets are computed for your birth minute and checked against Swiss Ephemeris. The bigger source of error is usually the birth time itself: if it’s rounded to the nearest hour, the Rising sign and house cusps can shift, while the planets barely move.
What if I don’t know my birth time?
Tick “I don’t know the time”. We calculate for noon and leave out the houses and the Rising sign instead of guessing them. If the Moon changed sign that day, the chart tells you its sign is uncertain.
Which house system do you use?
Placidus, the most common system in Western astrology. Close to the poles Placidus can’t be calculated for some birth times, and there we switch to whole-sign houses and say so on the chart.
Do you store my birth details?
Not in an account: there are no accounts. The details travel in the chart link so you can bookmark or share it. If you later order a book, they’re saved with that order only.
A whole book about your chart
The natal chart book is written from the same positions you see here: your big three, the ten planets, the twelve houses and your closest aspects, in plain language.