What a birth chart shows
A birth chart, also called a natal chart, is a map of the sky from the place and minute you were born. It lists where the Sun, the Moon and the eight planets from Mercury to Pluto were along the zodiac, plus two points astrologers use often: the North Node of the Moon and Chiron. The Ascendant (the sign rising in the east) and the Midheaven (the highest point of the zodiac at that moment) fix the chart to your birth place, and the twelve houses divide the sky into areas of life.
Astrologers read three things for each planet: the planet itself (what kind of energy), the sign (how it expresses itself) and the house (where in life it shows up). Venus in Leo in the 10th house, for example, reads as affection and taste (Venus) shown openly and generously (Leo) in career and public life (10th house).
How to read your result
The big three. The top of the result repeats your Sun, Moon and rising signs, the short summary most people start with. If your Ascendant is close to a sign change, a note says so.
The table. One row per body: sign, degree within the sign (0° to 29°59′) and house number. Rx marks a retrograde planet. In Placidus the Ascendant starts the 1st house and the Midheaven starts the 10th. In whole-sign houses the 1st house is the whole rising sign, and the Midheaven usually falls in the 9th, 10th or 11th house (farther north, sometimes the 8th or 12th).
Without a birth time. You get the planets' signs at local noon on your birth date, and no houses. Every planet except the Moon moves less than about 2° a day, so its sign is right unless it changed sign that day. The Moon can be off by up to about 8° either way; the moon sign calculator tells you whether it changed sign on your birth date.
The twelve houses in a few words
The traditional topics of each house, the same set used on this site's moon pages:
- 1st house: self, body, the way you start things
- 2nd house: money, possessions, what you value
- 3rd house: talk, siblings, short trips, learning
- 4th house: home, family, roots
- 5th house: romance, children, play, creative work
- 6th house: daily work, routines, health habits
- 7th house: partners, marriage, open rivals
- 8th house: shared money, debts, intimacy, endings
- 9th house: travel, higher education, beliefs
- 10th house: career, reputation, public role
- 11th house: friends, groups, hopes
- 12th house: solitude, rest, what is hidden
How the calculator works
The birth date, time and city become one moment in Universal Time, using the city's IANA time zone and the daylight saving rule in force on that date (the city list is about 34,000 places from GeoNames). For that moment the engine computes apparent geocentric positions in the tropical zodiac: the Sun, Moon and planets with astronomy-engine, Chiron from a NASA JPL Horizons table (through 2099), and the true node from the Moon's orbit. The Ascendant and Midheaven come from the local sidereal time and the city's coordinates; Placidus cusps divide the time each degree takes to rise into thirds. The engine is tested against NASA JPL Horizons for planet positions and against Swiss Ephemeris reference charts for the angles and house cusps; the numbers are on the methodology page. Dates from 1900 to 2100 are supported.
Astrology here is offered for entertainment and self-reflection. A birth chart describes tendencies and themes, not fixed outcomes.
Questions people ask
What do I need for a birth chart?
Your birth date, the time from your birth certificate and the city you were born in. Without a time you still get the planets' signs, but no houses, no Ascendant and no Midheaven, because those turn through the whole zodiac every day.
Placidus or whole-sign houses: which should I pick?
Placidus is the default in most Western astrology software and on most US sites, so it is the default here too. Whole-sign houses are the older system: each house is one whole sign, starting with your rising sign. The planets' signs are the same in both; only the house numbers can change, usually for planets near a house cusp. Placidus can't be calculated above about 66.5° latitude, so for births there the calculator uses whole-sign houses and says so.
What does Rx mean in my chart?
Rx marks a planet that was retrograde at your birth: seen from Earth it appeared to move backward through the zodiac. The Sun and Moon are never retrograde. The North Node is not marked, because its usual motion is backward.
Which North Node does this use?
The true node: the point where the Moon's actual orbit crosses the ecliptic at your birth. Some sites use the mean node, an averaged position. The two are usually within 1.5° of each other and are almost always in the same sign.
Why is my chart different from another site's?
Check the inputs first: birth time, a city with the right time zone, and the house system. If those match, signs and degrees should agree to within a minute of arc for the planets. Vedic (sidereal) charts differ by about 24°, so most placements move one sign back.
Do you store my birth data?
No. The chart is calculated in your browser. The date, time and place are not sent to a server and are not saved.
More calculators
- Rising sign calculator (Sun, Moon and rising only)
- Moon sign calculator (works without a birth time)
- All astrology calculators
By Dima Tretyak, a software developer who built this site and its calculation engine (not a professional astrologer). The explanations are AI-written from the engine's computed data and traditional astrology sources, then checked automatically. Updated October 23, 2026.