Reading a natal chart from the angles inward
A natal chart is two coordinates on one wheel: where each planet sat on the ecliptic, and which house that degree belonged to at that place and time. This page starts with one fixed chart you can click, then shows how each part was computed — and says plainly where computation stops.
Start with what you are asking
The chart is fixed once the birth data is fixed. Which part you read depends on the question — so start from the question, not from a planet's reputation.
Who am I
What does a chart say about a person?
The Ascendant and the sign on it describe how someone meets the world — the style of starting things. The Sun describes what is being expressed; the Moon, what is needed. Three different questions, often confused into one.
In the example chart the Ascendant is Virgo 16°31′, the Sun is Leo in the eleventh house, and the Moon is Sagittarius in the fourth. Three labels, three separate questions — not a personality summary.
The Ascendant moves about one degree every four minutes, so this is also the part that an unknown birth time destroys first.
Cast a chart and follow alongWork
Where does work sit in the chart?
The tenth house — from the Midheaven down to the next cusp — describes public position and the shape of a career. The sixth covers daily work and routine. Reading one without the other is the usual mistake.
The example Midheaven is Gemini 14°28′, so the tenth house runs from there; its ruler Mercury sits in the eleventh, in Leo, retrograde. That chain — cusp, ruler, where the ruler is — is the unit.
An empty house is not a missing answer. It means the subject is described through its ruler and through whatever is placed in it.
Cast a chart and follow alongTiming
Can a chart say when something happens?
A natal chart is one moment, frozen. Timing techniques — transits, progressions, returns — compare that moment with another one. They are separate computations built on top of this chart, not fields inside it.
This page computes the natal positions only: no transits, no progressions, no returns. What it prints is the fixed frame those techniques would be measured against.
Anything that dates an event is interpretation plus a technique. This page stops where the geometry stops.
Cast a chart and follow alongWhy so many versions
Why do different sites disagree about my chart?
Five inputs decide a chart: the ephemeris, the zodiac, the house system, the time-zone offset, and whether true solar time was applied. Change any one and the Ascendant or the cusps move — sometimes by a whole sign.
The example chart uses a tropical zodiac, Placidus houses, UTC+8 and no solar-time correction. Each of those is printed under the result, so a disagreement can be located instead of argued about.
Two charts that differ only in house system still agree on every planet's sign. If signs differ, something upstream changed.
Cast a chart and follow alongThese cards promise no outcome. They only say which part of the wheel a question lands in, and how far that part can go.
Cast a chart for a fixed birth moment
The calculator runs on this site's own endpoint: planets, true node, twelve Placidus cusps, the two angles and the major aspects. Every convention it used is printed under the result.
Nothing is saved. If you only want the fields explained first, the next section walks through a fixed example chart with exactly the same structure.
What each part of the wheel is doing
The chart above is a fixed example's real output, not your chart. Click the Ascendant, the Midheaven, the Sun, the Moon or any planet to highlight the explanation below it.
Example chart: born 8 August 1992, 08:00 (UTC+8), Beijing, Placidus houses — a tropical chart with no solar-time correction. It explains the wheel without exposing anyone's birth data.
Click a point on the wheel, or a value below it, to see what that part carries in this chart.
Ascendant · Virgo 16°
The degree rising on the eastern horizon; house 1 starts here.
Computed from the local sidereal time and the birthplace's latitude, which is why a chart without a birth time has no usable Ascendant: four minutes of clock error moves it about one degree, and two hours moves it a whole sign. Everything the houses are measured from hangs on this one number.
Keep reading →Midheaven · Gemini 14°
The degree culminating overhead; the start of house 10.
Where the local meridian crosses the ecliptic. It is independent of the Ascendant in the sense that it depends on sidereal time rather than on latitude as strongly, which is why two charts can share a Midheaven and differ on the Ascendant — and why the Midheaven alone is not enough to fix the houses.
Keep reading →Sun · Leo, house 11
One degree per day; the sign rotates once a year.
The Sun is the fastest-moving point after the Moon — about 1° per day, so its sign needs only a date, not a time. Here it is at Leo 15°42′ in the eleventh house: sign and house are separate coordinates, and this placement differs in house from the next sign along only because the cusps happen to fall where they do.
Keep reading →Moon · Sagittarius, house 4
About 13° per day; the sign changes every two and a half days.
The Moon is the reason a birth time matters even for people who do not care about houses: at roughly 13° per day it crosses a sign boundary every two to three days, so a chart cast at 23:00 on one day can disagree with one cast at 01:00 the next. Here it is at Sagittarius 15°43′ in the fourth.
Keep reading →Twelve cusps · Placidus
Uneven by design, and undefined beyond the polar circles.
Placidus divides the sky by how long a degree takes to rise, so house sizes vary with latitude: near the equator they are almost equal, and at high latitudes some houses become very large. Past the polar circles the system has no solution — this calculator refuses to cast a chart there rather than silently switching to another system.
Keep reading →Major aspects · 15 in this chart
Fixed angles, with an orb that is a convention.
An aspect is an angular distance between two planets: 0°, 60°, 90°, 120° or 180°, each with an allowed orb. The orb is not a measurement — different schools use different values — so this page prints the ones it used. Here 15 pairs fall inside those orbs, and the tightest is Sun trine Moon, off by about half an arcminute. Jupiter sits 1.5′ from the Ascendant yet appears in no row, because the angles are not planets — a good reminder that the aspect table only compares the eleven points.
Keep reading →Seven words that hold the system up
If you remember seven, remember these; everything else is a combination of them.
Tropical zodiacMeasured from the equinox, not from the constellations.
The sign of a planet is its ecliptic longitude divided into twelve 30° segments starting at the vernal equinox. Because of precession this no longer matches the constellations of the same name — a sidereal chart would put almost everything about 24° earlier. The two systems are not interchangeable, and mixing them is the most common source of a full-sign disagreement.
Tropical zodiac →AscendantThe rising degree; the first cusp.
The point of the ecliptic on the eastern horizon at the birth moment. It is a function of sidereal time and latitude, so it is the most time-sensitive number in the chart and the one an unknown birth hour destroys first.
Ascendant →MidheavenThe culminating degree; the tenth cusp.
Where the local meridian meets the ecliptic. It marks public position rather than private character, and it starts house 10 — which is why career questions usually begin there rather than at the Sun.
Midheaven →Twelve housesTwelve segments of the sky, each naming an area of life.
Houses are counted from the Ascendant, not from 0° Aries, and their boundaries depend on the house system. A planet's house says which area of life the chart assigns it to; its sign says where on the ecliptic it sat. The two are independent.
Twelve houses →PlacidusThe default house system in most Western practice.
It divides each day's arc by rising time, which produces uneven houses and no solution beyond the polar circles. The alternative systems — Koch, whole sign, equal — answer different questions and give different cusps from the same data.
Placidus →Aspects and orbsFixed angles between planets, with a tolerance.
Conjunction (0°), sextile (60°), square (90°), trine (120°), opposition (180°). The orb is how far the actual angle may sit from the ideal and still count. Because orbs are a convention, two sites using the same ephemeris can still print different aspect lists.
Aspects and orbs →RetrogradeAn apparent reversal, not a real one.
A planet appears to move backwards when Earth overtakes it in orbit. The chart marks it because traditional readings treat it as a different quality of expression, but the planet is not actually reversing — the speed column in the result shows the sign of the daily motion that produced the flag.
Retrograde →
How the five major aspects relate
Not an interpretation diagram: this is the geometry the aspect table is built from. Each aspect is a fixed division of the circle, and soft and hard aspects sit on opposite sides of it.
- Soft (flowing)
- Hard (friction)
0°
Conjunction: the two planets share a longitude. Read as fusion or emphasis, depending on the planets involved.
0° →60°
Sextile: one sixth of the circle. Traditionally the mildest of the major aspects, with the smallest orb.
60° →90°
Square: one quarter of the circle — the same distance as a right angle between the arms of the chart.
90° →120°
Trine: one third of the circle, the same step as the trigon groups. Traditionally read as the easiest of the five.
120° →180°
Opposition: the two planets face each other across the wheel, which is also why the seventh cusp is always the first plus 180°.
180° →
The diagram explains geometry, not meaning: an aspect is an angle, and whether it is read as easy or difficult is a convention on top of that angle. It does not say a placement is good — that needs a question, a school and a reading, none of which is computed here.
Twelve signs, eleven points, five aspects: the words on the chart
These are the labels the chart actually prints. Signs give the position on the ecliptic, points give what is being measured, aspects give the angles between them.
28 words
Aries
The first 30° of ecliptic longitude, starting at the vernal equinox. Cardinal fire: the segment that begins the cycle, which is why it is described in terms of starting rather than finishing.
Expand →Taurus
Fixed earth. In the natural zodiac it corresponds to the second house — but a planet in Taurus can fall in any house, because houses are counted from the Ascendant.
Expand →Gemini
Mutable air. The example chart's Midheaven falls here, which is why its tenth house begins in Gemini rather than in a fixed sign.
Expand →Cancer
Cardinal water, beginning at the summer solstice. Traded as the sign of the home and of what is kept, not of what is shown.
Expand →Leo
Fixed fire. In the example chart the Sun and Mercury both sit here, in the same house — a case where sign and house agree without being the same thing.
Expand →Virgo
Mutable earth. The example Ascendant is Virgo 16°31′, but the second cusp falls at Libra 11°32′ — so the first house spans two signs. That is the clearest illustration of why houses are not signs.
Expand →Libra
Cardinal air, beginning at the autumn equinox — the point opposite 0° Aries, which is why the two are described as a pair.
Expand →Scorpio
Fixed water. In the example chart Pluto sits here, in the third house: an outer planet's sign changes slowly, so its house is usually the more individual half of the reading.
Expand →Sagittarius
Mutable fire. The example Moon is here in the fourth house — a fast-moving point, so this placement is one that an inexact birth time can change.
Expand →Capricorn
Cardinal earth, beginning at the winter solstice. In the example chart Uranus and Neptune both sit here, and both fall in the fourth house — a pairing that comes from the two planets' slow motion, not from the sign.
Expand →Aquarius
Fixed air. The example Saturn is here in the fifth house, retrograde — the flag comes from the sign of the daily motion, not from the sign of the zodiac.
Expand →Pisces
Mutable water: the last segment, ending where Aries begins. The example chart has no planet here — an empty sign is normal and says nothing by itself.
Expand →Sun
The fastest point after the Moon. Its sign needs only a date; its house needs an exact time, because the house boundaries depend on the Ascendant.
Expand →Moon
The second fastest point, and the reason a birth time matters even to readers who ignore houses: it changes sign roughly every two and a half days.
Expand →Mercury
Never more than about 28° from the Sun, which is why Mercury is always in the Sun's sign or the one next to it. In the example chart it is in Leo, retrograde, in the eleventh house.
Expand →Venus
Like Mercury, an inner planet that stays near the Sun in the sky; its retrograde periods follow a repeating pattern of roughly eight years.
Expand →Mars
The first of the outer planets as seen from the chart's perspective of speed: it can be on either side of the Sun, and its retrograde periods are about two years apart.
Expand →Jupiter
In the example chart Jupiter sits 1.5′ from the Ascendant in the twelfth house. It is the tightest distance on the wheel, yet the aspect table does not list it: the Ascendant is an angle, not a planet, and the table only compares the eleven points.
Expand →Saturn
The slowest of the classical planets, spending about two and a half years in each sign. The example Saturn is in Aquarius, retrograde, fifth house.
Expand →Uranus
Spends roughly seven years in a sign, so its sign is shared by an entire generation; the house is what individualises it.
Expand →Neptune
About fourteen years per sign. In the example chart it shares Capricorn and the fourth house with Uranus, which is a common pairing for people born in the same few years.
Expand →Pluto
The slowest point on the wheel, spending between twelve and thirty years in a sign because of orbital eccentricity. Its sign is generational; its house is not.
Expand →True node
The point where the Moon's orbit crosses the ecliptic. It is always retrograde in the sense that it regresses through the zodiac in about 18.6 years. Chiron is not computed here — the chart lists it under "not computed" instead of printing a number.
Expand →Conjunction
Two points share a longitude. The orb is the widest of the five because a conjunction is recognizable even a few degrees off — which is exactly the kind of judgement the orb value encodes.
Expand →Opposition
Two points face each other across the circle. It is also the geometric relationship between the first and seventh cusps, which is why opposite houses are read as a pair.
Expand →Square
A quarter circle. Traditionally the hardest of the five to read as comfortable — but "hard" is a convention layered on the angle, not a property of it.
Expand →Trine
A third of the circle, the same step as the classical element trigons. Traditionally read as easy, with the caveat that easy aspects are not automatically good.
Expand →Sextile
A sixth of the circle, with the smallest orb of the five. Small orbs mean fewer sextiles survive a small birth-time error, which is why this list can change between two sites that otherwise agree.
Expand →A reading order that skips no steps
Fix the birth data, then leave it alone
Date, clock time, UTC offset and birthplace decide everything downstream. Changing one field to see what happens produces a different chart, not a sensitivity test.
Check the angles before reading any planet
Ascendant, Midheaven and the twelve cusps. If these disagree with another chart, the difference is one of the five conventions — not the interpretation.
Then the planets, sign and house separately
Read the sign for position on the ecliptic and the house for the area of life, and keep them apart. A planet can share a sign with another and still fall in a different house.
Add aspects with their orbs
An aspect without its orb is an unsourced claim. The tighter the orb, the more confident the reading can be — which is why this page prints both.
Stop at the geometry
Timing techniques — transits, progressions, returns — start from this chart but are separate computations. Turning a placement into a dated event is interpretation, and this page does not do it.
FAQ
What is a natal chart?
A map of where the planets stood at one moment, seen from one place on Earth. It records two things for each planet: its ecliptic longitude (which gives the sign) and which of the twelve houses that longitude fell into at that latitude. Angles, houses and aspects are all derived from those two.
Why does my Ascendant differ between sites?
Usually one of five things: a different house system, a different UTC offset (daylight saving is the classic), a true-solar-time correction one site applies and the other does not, a different ephemeris, or a sidereal rather than tropical zodiac. This page prints all five under the result so the difference can be found in one line.
Do I need an exact birth time?
For the planets' signs, a date is enough — except for the Moon, which changes sign every two to three days. For the Ascendant, the houses and every planet's house placement, you need the time to within a few minutes: four minutes of error moves the Ascendant about one degree.
Why is Chiron missing?
Chiron's orbit needs a dedicated ephemeris file that a pure TypeScript engine cannot reproduce at usable precision. Rather than print a plausible-looking number, the chart lists it under "not computed".
Is a chart a prediction?
No. It describes a structure at one moment. Predicting an event requires a timing technique on top of the chart, plus an interpretation — two steps this page does not take. The output here is geometry, and that is all it claims to be.
Astrology or BaZi?
Both start from a birth moment. BaZi reduces it to four pillars and reads element balance over long cycles; Western astrology spreads it over twelve houses and reads planet-and-angle placements. Neither is a substitute for the other, and both need the same birth data.
Chart first, study second
The calculator prints the ephemeris, zodiac, house system, true-solar-time shift and orbs it used. Any field you cannot read links straight to the article that explains it.