Free birth chart calculator
Enter your date, time and place of birth to see where the Sun, the Moon and the planets stood at that moment, and what your chart says.
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, the Moon and the eight planets stood along the zodiac, and which part of the sky was rising in the east.
Your Big Three
The Sun sign is the one most people know: it depends on your birthday. The Moon moves through a sign in about two and a half days, so it needs the date and often the time. The rising sign, or Ascendant, changes about every two hours, so it needs your birth time and place.
Houses and the birth time
The twelve houses divide the sky around your birthplace into areas of life. They turn once a day, so they need an exact time. Without one, you still get every planet's sign; the houses and the rising sign are left out rather than guessed.
A worked example
Here is a real chart, worked out the same way yours will be: someone born on March 2, 1994 at 3:30 pm in Chicago. It's an example birth, used on this page to show how a chart reads. Every position below is calculated, so you can check the steps against your own result.
| Planet | Sign | Degree | House | Motion |
|---|---|---|---|---|
| The Sun | Pisces | 12°04' | 8 | |
| The Moon | Scorpio | 18°33' | 4 | |
| Mercury | Aquarius | 22°55' | 7 | Retrograde |
| Venus | Pisces | 22°53' | 8 | |
| Mars | Aquarius | 26°24' | 7 | |
| Jupiter | Scorpio | 14°38' | 4 | |
| Saturn | Pisces | 3°57' | 7 | |
| Uranus | Capricorn | 24°56' | 6 | |
| Neptune | Capricorn | 22°35' | 6 | |
| Pluto | Scorpio | 28°04' | 4 |
How to read each part of your chart
A chart looks like a lot at once. Read it in this order and it comes together quickly: the Big Three first, then the planets, then the houses and the lines between them.
The Sun: who you are at the core
The Sun sign is the one you already know. It's where the Sun stood on your birthday, and astrologers read it as your identity and what you're here to grow into. In the example, the Sun is at 12°04' Pisces in the 8th house, so the sign says how this person shines and the house says where in life it shows most.
The Moon: what you need
The Moon is read as your inner life: how you feel, what comforts you, what you need to feel at home. It changes sign about every two and a half days, so plenty of people with the same Sun have different Moons. In the example, the Moon is at 18°33' Scorpio, in the 4th house.
The rising sign: how you come across
The rising sign, or Ascendant, is the sign coming up over the eastern horizon when you were born. It's read as your first impression and your way into new situations, and it sets the order of your houses. Here it's Leo, at 17°21'. Near the top of the chart sits the Midheaven, read as your public direction: Taurus at 7°38'.
The planets: each part of your life
Each planet is a part of you and its sign is how that part behaves. Mercury is how you think and talk, Venus what you love and value, Mars how you go after things, Jupiter where you grow, Saturn where you take responsibility. Uranus, Neptune and Pluto move so slowly that whole generations share their signs, so their house matters more than their sign. In the example, Mercury at 22°55' Aquarius in the 7th house describes a mind that works in Aquarius's way, on 7th house subjects.
Degrees: how far through a sign
Each sign spans 30 degrees, and the degree says how far through it a planet has moved. Degrees matter most when two planets sit at nearly the same degree of different signs, because that's what makes an aspect. They also tell you how close a planet is to the next sign: 29° is about to leave, and 0° has just arrived.
Houses: where it plays out
The twelve houses are the areas of life: the 1st is you, the 2nd what you have, the 7th partnership, the 10th your work and name. A planet's sign says how, and its house says where. Houses come from your birth time and place, because they follow the turn of the Earth, so they're the part of a chart that's most your own.
Aspects: how the parts talk
Aspects are the angles between planets. A conjunction, 0° apart, blends two planets. A sextile (60°) and a trine (120°) are read as easy. A square (90°) and an opposition (180°) are read as tension that gets things done. The closer to exact, the stronger. The tightest in the example is Venus sextile Neptune, within 0.3°.
Retrograde: planets that look backward
The word retrograde beside a planet means it appeared to move backward when you were born, seen from Earth. Astrologers read that part of you as more inward: it reviews before it acts. In the example, Mercury is marked.
Why the rising sign needs a birth time
Rising signs move fast. Every sign rises once a day as the Earth turns, so the sign changes about every two hours, although some signs rise faster than others depending on your latitude. Here is the example birth at six different times of the same day, in the same place:
| Born at | Rising sign |
|---|---|
| 00:00 | Scorpio |
| 04:00 | Capricorn |
| 08:00 | Aries |
| 12:00 | Cancer |
| 16:00 | Leo |
| 20:00 | Libra |
That's why we ask for a birth time, and why the answer changes without one. If you tick that you don't know it, you still get your Sun and every planet's sign, worked out for noon. We leave out the rising sign and the houses rather than guess them, and on a day the Moon changed sign we show both Moon signs. A birth certificate often has the time, and in some places the registrar can look it up.
How it is calculated
- Ephemeris: positions come from astronomy-engine 2.1.19, an open-source astronomy library. It computes each planet from its orbit, for the exact moment of birth.
- Checked: we compare 300 test birth charts from 1900 to 2030 against Swiss Ephemeris and NASA data on every code change. The Moon, the fastest body, has been at most 5.22 arcseconds from Swiss Ephemeris.
- Zodiac: the tropical zodiac most Western astrologers use, where 0° Aries is the point the Sun crosses in March.
- Houses: Placidus, the most widely used system. Very far north or south, where Placidus can't be calculated, we use Porphyry and say so.
- Time: your local birth time is turned into UTC with your birthplace's time zone rules as they were on that date, including daylight saving time.
- Place: the city you pick gives the latitude and longitude that set the rising sign and houses.
- Without a birth time: planets are worked out for noon, and the rising sign and houses are left out.
How we calculate the sky has the full method, the test results and tables you can check us against yourself.
How to read a birth chart
- Your big three: Sun, Moon and rising signThe three placements astrologers read first, and what each shows.
- The 12 houses in astrologyThe twelve areas of life a birth chart divides into.
- Aspects in astrologyThe angles between planets, and what each is read as.
- What the planets mean in a birth chartThe role each planet plays, from the Sun to Pluto.
- How to read your birth chart step by stepSix steps from the big three to the aspects.