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A free online natal chart calculator — read it with your own AI
ChatGPT hallucinates planet positions, but it reads them beautifully. We handle the astronomy: your chart is computed to the arc second and handed over as ready-made text — just paste it into the chat.
The toolkit
What you can do here
Natal chart
A free birth chart with planets in signs and houses, aspects, house cusps and 10 house systems. Arc-second precision, an AI reading — or copy the prompt into your own AI.
Synastry
Relationship compatibility by birth dates: a bi-wheel of two charts, inter-aspects between planets, and an AI interpretation of your connection.
Business synastry
Partner compatibility for work: a score across five business domains — from communication to shared goals — with a dedicated AI analysis.
Numerology
Numbers instead of planets: today's personal day, a full profile from your name and birth date, and the Pythagorean square from its digits.
Try it on someone you know
Copy a ready-made prompt built from a famous person's real birth data, paste it into your AI chat, and see how closely the read-out matches their life.
Physicist, relativity
=== NATAL CHART ===
Name: Albert Einstein
Birth: 1879-03-14T11:30
Place: Ulm
Coords: 48.4011°N, 9.9876°E
Timezone: Europe/Berlin
House system: placidus
Zodiac: tropical
--- ANGLES ---
ASC: 8°49' Cancer
MC: 9°12' Pisces
DSC: 8°49' Capricorn
IC: 9°12' Virgo
--- PLANETARY POSITIONS ---
Sun 23°29' Pisces H10
Moon 14°23' Sagittarius H6
Mercury 3°07' Aries H10
Venus 16°58' Aries H11
Mars 26°54' Capricorn H8
Jupiter 27°28' Aquarius H9
Saturn 4°11' Aries H10
Uranus 1°17' Virgo H3 ℞
Neptune 7°52' Taurus H11
Pluto 24°43' Taurus H11
NorthNode 2°43' Aquarius H8 ℞
SouthNode 2°43' Leo H2 ℞
Chiron 5°32' Taurus H11
Lilith 27°58' Aries H11
Ceres 17°19' Taurus H11
Pallas 10°01' Aries H10
Juno 25°27' Aries H11
Vesta 9°45' Cancer H1
PartOfFortune 29°43' Pisces H10
--- HOUSE CUSPS ---
H 1: 8°49' Cancer
H 2: 25°52' Cancer
H 3: 14°47' Leo
H 4: 9°12' Virgo
H 5: 13°59' Libra
H 6: 29°07' Scorpio
H 7: 8°49' Capricorn
H 8: 25°52' Capricorn
H 9: 14°47' Aquarius
H10: 9°12' Pisces
H11: 13°59' Aries
H12: 29°07' Taurus
--- DOMINANT / BALANCE ---
Chart Ruler (Almuten): Moon (ruler of Cancer Ascendant)
Elements: Fire 40% (Mercury, Venus, Saturn, Moon), Earth 40% (Mars, Neptune, Pluto, Uranus), Air 10% (Jupiter), Water 10% (Sun)
Modalities: Cardinal 40% (Mercury, Venus, Saturn, Mars), Fixed 30% (Neptune, Pluto, Jupiter), Mutable 30% (Moon, Uranus, Sun)
(balance counts the ten Sun-Pluto bodies only — the Ascendant, MC, nodes, Chiron, Lilith and the asteroids are NOT part of it and must not be added to a group.)
--- ASPECTS ---
(the aspects this reading interprets: the chart's tightest, numbered tightest-first. This is the whole set — there is no wider aspect waiting to be promoted into it.)
#1 Mercury conjunction Saturn orb 1°04'
#2 Sun sextile Pluto orb 1°14'
#3 Mars trine Pluto orb 2°11'
--- ALSO PRESENT IN THE CHART (reference only — never interpret) ---
(too wide to carry the reading. A North Node / South Node opposition here is exactly 0°00' by construction — an artifact of how the nodes are derived, not a contact.)
Moon trine Venus 2°35', Jupiter square Pluto 2°45', Sun sextile Mars 3°25', Jupiter opposition Uranus 3°48', Uranus trine Neptune 6°35'
--- AI INSTRUCTION ---
Act as a professional and insightful astrologer. Please provide a detailed, well-structured reading of this natal chart.
IMPORTANT: Use ONLY the positions, houses and aspects listed above. Do NOT recalculate or guess any planetary positions — the data above is computed by the backend and is exact.
Focus on the following topics:
- Analyze the core personality (Sun, Moon, Ascendant).
- Describe the overall life path and dominant traits.
- Interpret the aspects in the ASPECTS list: all of them, and only them. Name each row's number as you interpret it, and do not re-derive orbs from the positions.
- The ALSO PRESENT block is reference data, not material: those aspects are too wide to read. Never give one a section, a paragraph, a bullet or a heading anywhere in the reading — at most a clause inside a sentence you are already writing, and only where the point needs it.
- Quote the exact degree and sign of every placement you interpret (e.g. "Sun 20°39' Leo, house 12") and the orb of every aspect you name. Do not interpret in signs and houses alone.
- Address the element/modality balance whenever a group reaches 40% or more: quote its percentage exactly as printed above (never recompute it — a reading turned a printed "Fire 50%" into "60%, if counted properly"), name that group, take its members from the Elements/Modalities lines above exactly as listed (never work out the membership yourself) but write those body names in the language of your response rather than copying the English spelling, and say what the concentration does to this person — mentioning a group that is genuinely at 0% only if there is one, never announcing an "empty group" that the percentages above do not show. Never re-sort a body into an element or modality yourself, and never leave a lopsided balance unmentioned — omitting it is as wrong as miscounting it. Mark a planet as retrograde EVERY time you interpret it, not only on first mention — but ONLY when ℞ stands on that body's own row above. Asked to always flag it, a reading wrote "both retrograde" of a Moon-Uranus trine where only Uranus carries the marker: never spread it across the two bodies of an aspect, and never call the Sun or the Moon retrograde — they never are.
- The aspect data is complete: if two bodies appear together in neither the ASPECTS list nor an ALSO PRESENT block, they DO NOT aspect each other, however close they look. Never call a pair conjunct, square or trine unless that exact row exists above. Bodies in the same house or sign are a stellium/grouping — say "together in house 12", never "conjunction", unless the row is listed. An aspect exists ONLY as a numbered row above. There is no such thing as an aspect that is "implied", "seen from the overall picture", "in the background" or "not listed but visible" — if you cannot cite its row number, it does not exist, and hedging the claim does not make it sayable.
- The lunar nodes and the angles do not count against the aspect limit above. Cover the North/South Node axis (its signs and houses) as the life-direction theme, and use the Ascendant, Midheaven and Descendant when they carry the point you are making.
- NO aspects to the angles are computed — the ASPECTS list is body-to-body only. Read the angles from the ANGLES block as positions; never assert an aspect between a body and an angle.
- Be honest and objective: highlight the main internal contradictions, blind spots, and potential pitfalls, and suggest practical ways to work with them.
- Avoid generic astrological phrases and Barnum statements — anything that would be true of almost anyone ("sensitive inside but composed outside", "you are intelligent and well-read") is a failure, however well it fits. Every claim must be traceable to a specific placement or aspect above. Write about this person, not about a personality type.
FORMAT: Provide a well-balanced, medium-length reading (about 2-3 pages of text).
STRUCTURE: Organize the reading under clear thematic headings. End with a "Key takeaways" list of the 3 most important points, then offer the user 3 follow-up questions they could ask to explore their chart further.
TONE: Write in the voice of a psychological astrologer — the language of self-discovery and inner patterns, gentle but honest framing, with a focus on growth and integration.
Write your entire response in English — every heading, label and sentence. Any English label above is input data, not output: translate it rather than copying it verbatim.AI + Astronomy
Why not just ask ChatGPT?
AI on its own
Language models don't run astronomical calculations. Ask one for your birth chart and it will confidently invent planet degrees, houses — sometimes even signs.
AI + AstroAxis
We compute the real positions with a professional astronomical engine — the standard professional astrologers rely on — and format them into a structured prompt your AI can interpret without guessing.
In three steps
How it works
- 1
Enter your birth data
Date, time and place of birth. City search and time zones are handled automatically — including historical DST.
- 2
Get your chart instantly
The wheel, planet positions, houses and aspects are computed server-side by a professional astronomical engine in a second.
- 3
Read it your way
Get a short AI reading right here — or press “Copy for AI” and paste the precise data into ChatGPT, Claude or any model you already pay for.
Your natal chart reading, inside your own AI chat
Press “Copy for AI” and a ready-made request lands on your clipboard: exact planet positions, houses, aspects and interpretation instructions. Paste it into ChatGPT, Claude, Gemini or whichever AI you already use, and within seconds you get a detailed reading built on real astronomical data rather than the model's guesswork.
The answer won't be a generic template: the AI works from your own degrees, minutes and seconds, so the reading is as individual as the chart itself.
A conversation, not a one-off report
The difference from a usual PDF reading is that the chat stays with you. You can ask follow-up questions: why the Moon in this house shapes your closest relationships, what a Mars–Saturn square really means, what to watch for in your career. The AI remembers your chart and answers in the light of everything you've discussed before.
Guidance on any area of life
In the same chat you can explore career and money, relationships and family, health and inner resources, strengths and growth points. Come back whenever a new question appears — the chart is already loaded, so there's nothing to explain again.
Convenient, free and always at hand
The chart and the AI request are free — no sign-up, no subscription. The chat lives in an app you already use every day, on your phone and your computer, so a personal astrological reading stays a couple of taps away.
What is a natal chart?
A natal chart (birth chart) is a map of the sky at the exact moment and place of your birth. It records the positions of the Sun, Moon and planets in the zodiac signs and astrological houses, and the angular relationships between them — the aspects. Astrologers read this combination as a portrait of character, talents and recurring life themes.
To calculate a natal chart you need three things: the date of birth, the time as precise as possible, and the place. The time matters most — the Ascendant and the house cusps shift about one degree every four minutes, so even a 15-minute error can move planets into neighboring houses.
Planets, houses and aspects
The planets show what acts in you, the signs — how it acts, the houses — where in life it plays out, and the aspects — how these forces combine. AstroAxis computes all of it: the 10 planets, the lunar nodes, Chiron, Lilith, the major asteroids and the Part of Fortune, with 10 house systems from Placidus to Whole Sign.
Why precision matters
Free calculators often round positions or use simplified models. AstroAxis runs the same astronomical standard as professional software — so every degree, minute and second in your chart is real. That is also why our “Copy for AI” prompt works: the AI interprets exact data instead of hallucinating it.
Live example
This is what a natal chart looks like
A live example computed by our engine — in the calculator every element is interactive.
Signs
The outer ring holds the 12 zodiac signs; the sign a planet occupies colors how it expresses itself.
Planets
Glyphs with degree marks are the planets and chart points — Sun, Moon, Mercury and beyond.
Houses
The 12 numbered sectors are houses — life areas from self (1st) to career (10th).
Aspects
Lines in the center are aspects — angular links between planets, harmonious or tense.
Answers