What a birth chart shows
A birth chart, or natal chart, is a map of the sky at the moment you were born, seen from your birthplace. Astrologers read three layers in it: the planets (what kind of energy), the signs they were in (how that energy is expressed) and the houses they fall in (where in life it shows up). The angles between planets, called aspects, describe how those energies work together.
The planets and points
- ☉︎ Sun
- Identity, vitality and what you are here to express.
- ☽︎ Moon
- Emotions, instincts and what makes you feel safe.
- ☿︎ Mercury
- Thinking, learning and communication.
- ♀︎ Venus
- Love, attraction, pleasure and values.
- ♂︎ Mars
- Drive, courage, anger and desire.
- ♃︎ Jupiter
- Growth, luck, faith and where you expand.
- ♄︎ Saturn
- Discipline, limits, responsibility and long-term work.
- ♅︎ Uranus
- Change, freedom, originality and sudden breaks.
- ♆︎ Neptune
- Imagination, ideals, spirituality and illusion.
- ♇︎ Pluto
- Power, intensity and deep transformation.
- ☊︎ North Node
- The direction of growth astrologers associate with your life path.
- ⚷︎ Chiron
- A lasting sensitivity and the wisdom that grows from it.
- ⚸︎ Lilith
- What is wild, refused or kept in the shadow.
- Ascendant
- How you come across and approach new situations.
- Midheaven
- Career direction, reputation and public life.
The twelve houses
- First house: self, body and first impressions.
- Second house: money, possessions and self-worth.
- Third house: communication, siblings, neighbors and short trips.
- Fourth house: home, family, roots and private life.
- Fifth house: creativity, romance, play and children.
- Sixth house: daily work, routines, service and health habits.
- Seventh house: partnership, marriage and open rivals.
- Eighth house: shared resources, intimacy, debt and transformation.
- Ninth house: higher learning, travel, beliefs and publishing.
- Tenth house: career, status, reputation and public role.
- Eleventh house: friends, groups, networks and hopes.
- Twelfth house: solitude, the unconscious, retreat and hidden matters.
House systems
All house systems agree on the signs your planets are in. They differ in where the house boundaries fall.
- Placidus divides the time each degree takes to travel between the horizon and the meridian into equal thirds. It is the default in most modern software, but it cannot be drawn inside the polar circles; there the calculator switches to Porphyry and tells you.
- Whole Sign makes the whole rising sign the first house, the next sign the second house, and so on. It is generally considered the oldest system, and it works at any latitude.
- Equal starts the first house at the exact Ascendant degree and makes every house 30 degrees.
- Porphyry divides each quarter of the chart between the angles into three equal parts.
Aspects
- Conjunction
- The two energies blend and act as one.
- Opposition
- A pull between two sides that asks for balance.
- Trine
- An easy flow of talent between the two.
- Square
- Friction that pushes you to act and grow.
- Sextile
- An opportunity that rewards a little effort.
The calculator allows an orb of 8° for conjunctions and oppositions, 7° for trines and squares and 5° for sextiles, 2° more when the Sun or Moon is involved, and 3° for the Node, Chiron, Lilith and the angles.
How accurate is it?
Every position is checked against the Swiss Ephemeris, the reference behind most professional astrology software. For births from 1900 to 2099 all planets and points come out within two arcminutes, and most within a few arcseconds. House cusps match to within three arcseconds for Placidus, Whole Sign, Equal and Porphyry houses. The about page explains the method.
Questions
Do I need my exact birth time?
For the planets in signs, usually not: the date is enough except for the Moon on some days, and for any planet that changes sign on your birth day. For the Ascendant, the Midheaven and the houses, yes. They change every few minutes, so use the time on your birth certificate.
Which house system should I choose?
Placidus is the most common in modern Western astrology and is the default here. Whole Sign houses are generally considered the oldest system and are popular with traditional and Hellenistic astrologers. Try both: the planets stay in the same signs, only the house boundaries move.
What does the R next to a planet mean?
It marks a planet that was retrograde at your birth, appearing to move backward through the zodiac as seen from Earth. Astrologers read retrograde planets as working in a more inward or reflective way.
Why is my Lilith different on another site?
There are several Liliths. This calculator uses the mean Black Moon Lilith, the default in most astrology software. Sites that use the true (osculating) Lilith can differ by up to about 30 degrees.
Is my birth data stored?
No. The whole chart is calculated in your browser. If you share a result link, the birth details are part of that link.