AI astrology · a test you can run · 2026
Is ChatGPT good at astrology? Test it.
Three computed reference charts, each with a trap. Paste the prompt, type back the answer, and see whether your chatbot calculated a chart or improvised one.
Photo: Jakub Żerdzicki / Unsplash
At a glance
Good at explaining, unreliable at calculating. Check any chart it gives you: Chart C's Moon sits at 29°39′ Virgo and changes sign 40 minutes later.
- Daylight-saving trap
- Leo rising, not VirgoChart A, Chicago
- Cusp trap
- Sun 0°04′ ScorpioChart B, 103 min after the ingress
- Moon trap
- Moon 29°39′ VirgoChart C, Libra in 40 min
- Reference engines agree
- Planets to under 1″JPL DE442 vs Swiss Ephemeris
Score your chatbotCopy a prompt, type back the answer, get a score.
The short answer
Is ChatGPT good at astrology? It depends which half you ask for
Try this today
- Ask your chatbot "How did you calculate that?" If it can't point to a calculation or a tool run, treat the positions as guesses.
- Compare its answer with a calculator before you read a single paragraph of interpretation.
- Keep the two jobs apart: get the chart from a calculator, then ask the AI what it means.
How Shymea's AI astrology worksGet your chart computed first
It's late, and you've just typed your birthday into ChatGPT. Three seconds later there's a confident answer: a Moon sign, a rising sign, a paragraph about why you overthink texts. It sounds like you. But is it your chart?
Astrology asks a chatbot to do two very different jobs. Job one is astronomy: turning a date, time and place into planetary positions, a rising sign and houses. That is arithmetic on an ephemeris, a table of where the planets were. Job two is interpretation: explaining what Moon in Scorpio or Saturn in the 8th house means in plain words. That is language.
Large language models are built for job two. They write by predicting likely text. Unless the model actually runs a calculation (some versions of ChatGPT can execute code or search the web) or you hand it the positions, the numbers it gives you come from the same text prediction as everything else. Sometimes that lands. Sometimes it lands one sign over. You can't tell which by reading the answer, because the wrong chart is written just as smoothly.
So we're not going to tell you ChatGPT scored 7 out of 10. We haven't published a scored run, and model versions change often enough that one would go stale fast. Instead, this page gives you three reference charts computed from NASA JPL's DE442 ephemeris, each built around a known trap, plus a scorer. Five minutes, any chatbot, and you'll have your own answer.
Full disclosure: Shymea is our app, and its readings use AI too, through Microsoft's Azure OpenAI Service. We built it the other way round: the chart is computed first, and the model only explains what was calculated. That's exactly the split this test checks for.
The test
Three charts, one prompt each, scored against the sky
Try this today
- Open a brand-new chat. Turn memory or custom instructions off if you can, so it can't lean on anything you told it before.
- Paste the prompt exactly. Don't add hints.
- Write down the model name, the date, and whether it ran code, browsed or used a plugin.
- Run it three times in three fresh chats. Different answers to the same question tell you something too.
None of these birth data belong to a real person. Each chart is a moment we chose because it's easy to get slightly wrong, and slightly wrong is all it takes to change a sign.
Chart A, the daylight-saving chart: July 8, 1995 at 8:30 a.m., Chicago, Illinois, USA. Daylight saving time was in force. Software that uses standard time puts the birth an hour off.
Chart B, the cusp chart: October 24, 1999 at 4:05 a.m., Mumbai, Maharashtra, India. The Sun had changed sign less than two hours earlier, and India keeps a half-hour time zone.
Chart C, the edge-of-the-moon chart: March 25, 2005 at 11:20 a.m., Stockholm, Sweden. The Moon was minutes from changing sign, Mercury was retrograde, and Stockholm sits at 59 degrees north, where some signs rise very fast.
The prompt gives only what a person would know: date, local clock time and city. It doesn't mention the time zone, daylight saving or the trap, because working those out is part of the job. Use the scorer below to paste in what the chatbot said.
How strict to be. Two independent engines (JPL DE442 through Skyfield, and the Swiss Ephemeris) agree on every planet in these charts to under 1″ and on the angles to 10″. So a calculated answer should get every sign right and land within about 1° on the degrees. Several degrees out, or a sign off, means the chart wasn't calculated properly.
The sky behind it
Reference method. skyfield 1.53 + JPL DE442; geocentric apparent ecliptic longitude, true ecliptic and equinox of date (tropical zodiac); Mars to Pluto use system barycenters. Ascendant and MC from Greenwich apparent sidereal time and true obliquity. Placidus cusps from the Swiss Ephemeris house routine with the same UT. Every position cross-checked against pyswisseph 2.10.03; failure threshold 0.02 deg. Rising-sign durations are from a 2-minute scan over the chart's day. Generated 2026-10-18.
Trap 1
The clock trap: daylight saving and half-hour time zones
Try this today
- If your chatbot gave Chart A Virgo rising, it probably ignored daylight saving time.
- Born somewhere with a half-hour or 45-minute zone (India, Newfoundland, parts of Australia, Nepal)? Check your own chart twice.
- Look up your birth time on your birth certificate. Family memory of "around breakfast" is a different test.
Every chart starts by turning the local clock time into Universal Time. Get the offset wrong and the whole chart slides with it.
Chart A. In Chicago on July 8, 1995, clocks were on daylight saving time, UTC−5. Worked out properly, the rising sign is 21°43′ Leo. Use standard time instead and the birth moves an hour, so the rising sign becomes 3°22′ Virgo. Treat the time as if it were already UTC and you get 19°01′ Gemini rising. Same person, three rising signs.
Chart B. India runs on UTC+5:30, a half-hour zone. Drop the half hour and Chart B's rising sign moves from 23°52′ Virgo to 0°59′ Libra. The local date is October 24, but in UTC the birth falls on October 23, the evening before. A tool working in the wrong date can be off by a whole day of Moon movement.
The planets barely notice an hour. The Moon moves about half a degree, the Sun a few arcminutes. The Ascendant is different: it moves through all twelve signs in a day, so one hour can carry it into the next sign.
Trap 2
The edge trap: planets sitting on a sign boundary
Try this today
- If a chatbot gives you a planet at 0° or 29° of a sign, verify that one first.
- Ask it for degrees and minutes, not only signs. Vague answers hide edge mistakes.
- Born on the day the Sun changed sign? Your Sun sign depends on the exact minute, not the date.
A sign is 30° wide. When a planet sits mid-sign, a rough estimate still lands in the right place. When it sits on the edge, only a real calculation will do.
Chart B's Sun is at 0°04′ Scorpio. The Sun had entered Scorpio 103 minutes before this birth, so it was 4.3′ (arcminutes) inside the sign. An estimate off by a tenth of a degree turns this Scorpio into a Libra. The same chart has Jupiter at 29°54′ Aries, retrograde, one more edge to catch.
Chart C's Moon is at 29°39′ Virgo and moves into Libra 40 minutes after the birth. The Moon moves about 0.53° an hour here, so it's the fastest-moving trap in the set. Treat the Stockholm time as UTC and the Moon comes out 0°11′ Libra, a different sign.
Chart C also has Mercury retrograde at 12°17′ Aries. Retrograde status is a simple yes or no, and in this test it's checked separately for every planet from Mercury to Pluto. In Chart C the reference retrogrades are Mercury and Jupiter.
Trap 3
The horizon trap: rising signs and houses
Try this today
- Always ask "Which house system did you use?" A good answer names one.
- Unsure of your birth time? See every rising sign your birth day allows instead of trusting one answer.
- Compare Placidus and Whole Sign for your own chart before you read house meanings.
People assume each rising sign lasts two hours. Near the equator that's roughly true. Further from it, it isn't.
On Chart C's date in Stockholm, 59° north, Aries took about 32 min to rise, while Leo took about 3 h 12 min. In Mumbai, Maharashtra, close to the tropics, the range was much narrower: 1 h 36 min to 2 h 14 min. Any shortcut that assumes two hours per sign falls apart in the north.
Chart C's rising sign is 1°20′ Leo, only 9 minutes into the sign. Fifteen minutes earlier it was 28°55′ Cancer. That's an honest limit of astrology too: if the birth time on record is a rounded guess, nobody, human or machine, can promise the rising sign.
Houses add another layer. The prompt asks for Placidus houses, the default on most Western sites. Many astrologers prefer Whole Sign houses instead. Across these three charts, 18 planet placements fall in a different house depending on the system, and Chart C alone has 7. If a chatbot never says which system it used, its houses can't be checked at all.
What it's good for
Where ChatGPT is genuinely useful for astrology
Try this today
- Start your prompt with "Here is my computed chart:" and paste the placements, so the model interprets instead of calculating.
- Ask it to tell you which statements come from the chart and which are general astrology.
- If an answer scares you, close it. Astrology is a tradition for reflection, not a forecast.
None of this means you should close the tab. Explaining is the job language models were built for, and astrology has plenty to explain.
Paste in placements from a calculator and a chatbot can turn "Venus square Saturn" into something you understand, suggest journal prompts, compare two interpretations, or explain the difference between a trine and a sextile. It's patient at 1 a.m., and that counts for something.
Keep its limits in view. A chatbot doesn't know your life. It can sound certain about things astrology itself treats as open, and it can't make predictions any more than a book can. OpenAI's own help pages say ChatGPT can be wrong while sounding confident, and Google's Gemini help pages warn that it may produce inaccurate information. Treat the reading as a mirror for reflection, not a verdict.
Try it
Grade your chatbot's chart
Pick a test chart, copy the prompt into ChatGPT, Gemini, Meta AI or any chatbot, then type back the signs and degrees it gives you. The scorer compares them with the computed reference and tells you which slip explains each miss.
Step 1. Pick a test chart
The trap: Daylight saving time was in force. Software that uses standard time puts the birth an hour off.
Step 2. Copy this into a new chat
Step 3. Type in what it said
Sign is enough. Add the whole degree if it gave one (for 21°43′, type 21). Leave a row blank if it skipped it.
Which planets did it call retrograde?
More to read
Shorter reads. Each opens in place.
Gemini, Meta AI and the rest
Is Gemini or Meta AI better at astrology than ChatGPT?
We haven't scored them, so we won't rank them. The test works on any chatbot: Gemini, Meta AI, Claude, Copilot, a horoscope app with a chat box.
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What matters is the same for all of them: did it calculate, or did it write? Run the three prompts, score them, and compare models on the same day. Results can shift when a model updates, so note the date next to every score.
Honesty box
What this page does and doesn't claim
It claims: the reference positions, the slips and the rising-sign durations, all computed and cross-checked (planets agree to under 1″ between two engines).
Continue readingShow less
It doesn't claim: any accuracy score for ChatGPT, Gemini or Meta AI, or that astrology predicts events. We publish the test so the scores are yours, made on the day you run it.
The reference charts
The answers, in full. Positions are geocentric, tropical, to the nearest arcminute. Peek after you've scored, or the test is too easy.
| Point | Position | Retrograde | Placidus house | Whole Sign house |
|---|---|---|---|---|
| Sun | 15°56′ Cancer | No | 11 | 12 |
| Moon | 21°25′ Scorpio | No | 4 | 4 |
| Mercury | 26°36′ Gemini | No | 11 | 11 |
| Venus | 4°01′ Cancer | No | 11 | 12 |
| Mars | 22°35′ Virgo | No | 2 | 2 |
| Jupiter | 6°29′ Sagittarius | Yes | 4 | 5 |
| Saturn | 24°45′ Pisces | Yes | 8 | 8 |
| Uranus | 29°01′ Capricorn | Yes | 6 | 6 |
| Neptune | 24°24′ Capricorn | Yes | 6 | 6 |
| Pluto | 28°04′ Scorpio | Yes | 4 | 4 |
| Rising (Ascendant) | 21°43′ Leo | 1 | 1 | |
| Midheaven (MC) | 13°21′ Taurus | 10 |
| Point | Position | Retrograde | Placidus house | Whole Sign house |
|---|---|---|---|---|
| Sun | 0°04′ Scorpio | No | 2 | 3 |
| Moon | 17°14′ Aries | No | 7 | 8 |
| Mercury | 24°10′ Scorpio | No | 3 | 3 |
| Venus | 13°46′ Virgo | No | 12 | 1 |
| Mars | 5°00′ Capricorn | No | 4 | 5 |
| Jupiter | 29°54′ Aries | Yes | 8 | 8 |
| Saturn | 14°47′ Taurus | Yes | 8 | 9 |
| Uranus | 12°52′ Aquarius | No | 5 | 6 |
| Neptune | 1°37′ Aquarius | No | 5 | 6 |
| Pluto | 8°52′ Sagittarius | No | 3 | 4 |
| Rising (Ascendant) | 23°52′ Virgo | 1 | 1 | |
| Midheaven (MC) | 24°03′ Gemini | 10 |
| Point | Position | Retrograde | Placidus house | Whole Sign house |
|---|---|---|---|---|
| Sun | 4°52′ Aries | No | 10 | 9 |
| Moon | 29°39′ Virgo | No | 4 | 2 |
| Mercury | 12°17′ Aries | Yes | 10 | 9 |
| Venus | 3°25′ Aries | No | 10 | 9 |
| Mars | 3°23′ Aquarius | No | 7 | 7 |
| Jupiter | 15°09′ Libra | Yes | 4 | 3 |
| Saturn | 20°24′ Cancer | No | 12 | 12 |
| Uranus | 8°20′ Pisces | No | 9 | 8 |
| Neptune | 16°47′ Aquarius | No | 8 | 7 |
| Pluto | 24°31′ Sagittarius | No | 5 | 5 |
| Rising (Ascendant) | 1°20′ Leo | 1 | 1 | |
| Midheaven (MC) | 25°41′ Pisces | 10 |
| Chart | Slip | Rising sign becomes | Moon becomes |
|---|---|---|---|
| A (correct) | Worked out properly | 21°43′ Leo | 21°25′ Scorpio |
| A | Daylight saving time ignored (standard time used) | 3°22′ Virgo | 22°01′ Scorpio |
| A | Birth time treated as UTC | 19°01′ Gemini | 18°24′ Scorpio |
| A | Birth time off by 15 minutes (earlier) | 18°48′ Leo | 21°15′ Scorpio |
| A | Birth time off by 15 minutes (later) | 24°37′ Leo | 21°34′ Scorpio |
| B (correct) | Worked out properly | 23°52′ Virgo | 17°14′ Aries |
| B | Half hour dropped (UTC+5 used instead of UTC+5:30) | 0°59′ Libra | 17°33′ Aries |
| B | Half hour rounded up (UTC+6 used) | 16°46′ Virgo | 16°56′ Aries |
| B | Birth time treated as UTC | 9°54′ Sagittarius | 20°35′ Aries |
| B | Birth time off by 15 minutes (earlier) | 20°19′ Virgo | 17°05′ Aries |
| B | Birth time off by 15 minutes (later) | 27°26′ Virgo | 17°24′ Aries |
| C (correct) | Worked out properly | 1°20′ Leo | 29°39′ Virgo |
| C | Birth time treated as UTC | 10°48′ Leo | 0°11′ Libra |
| C | Birth time off by 15 minutes (earlier) | 28°55′ Cancer | 29°31′ Virgo |
| C | Birth time off by 15 minutes (later) | 3°44′ Leo | 29°47′ Virgo |
| Rising sign | Chicago (1995-07-08) | Mumbai (1999-10-24) | Stockholm (2005-03-25) |
|---|---|---|---|
| Aries | 70 | 96 | 32 |
| Taurus | 84 | 106 | 46 |
| Gemini | 114 | 122 | 94 |
| Cancer | 144 | 134 | 162 |
| Leo | 154 | 132 | 192 |
| Virgo | 152 | 128 | 192 |
| Libra | 154 | 128 | 190 |
| Scorpio | 154 | 132 | 192 |
| Sagittarius | 144 | 134 | 164 |
| Capricorn | 112 | 122 | 94 |
| Aquarius | 86 | 106 | 46 |
| Pisces | 68 | 96 | 32 |
All times are UTC. In the Americas the local date can be a day earlier; in Asia and Australia a day later.
Quick answers
Is ChatGPT good at astrology?
It's good at explaining astrology and unreliable at calculating charts unless it runs a real calculation. A language model writes by predicting text, so positions it hasn't calculated can be wrong while sounding right. Test it with the three reference charts on this page, for example Chart C, whose Moon is at 29°39′ Virgo.
Is ChatGPT accurate for birth charts?
Sometimes, and you can't tell from the wording. Check its placements against a calculator. Accurate software agrees to within arcseconds, so a sign off or several degrees out means it didn't calculate the chart properly. Our scorer checks signs, degrees and retrogrades.
Can ChatGPT read my birth chart?
It can interpret a chart you give it. For the chart itself, get your placements from an ephemeris-based calculator first, then paste them in and ask what they mean. That way the model explains instead of guessing positions.
Is AI astrology accurate in 2026?
Accuracy has two parts. The astronomy can be exact if the app calculates from an ephemeris such as NASA JPL's DE442. The interpretation is a tradition, not a measurable prediction. Ask any AI astrology app how it gets its positions.
Why did ChatGPT give me the wrong rising sign?
Most likely a time problem: daylight saving time, a half-hour time zone, or treating local time as UTC. In Chart A, ignoring daylight saving moves the rising sign from Leo to Virgo. The Ascendant changes sign every couple of hours, faster or slower depending on latitude.
Is Gemini or Meta AI better than ChatGPT for astrology?
We haven't published scores for any of them, so we won't rank them. Run the same three prompts on each on the same day and score them here. Note the model and date, because results can change when models update.
How do I check if an AI got my chart right?
Compute your chart with an ephemeris-based calculator, then compare sign, degree and retrograde status for each planet, plus your rising sign and Midheaven. Ask the AI which house system it used. Start with any planet at 0° or 29° of a sign.
Does Shymea use AI for readings?
Yes, and we say so: Shymea's readings use AI through Microsoft's Azure OpenAI Service. The chart is computed first from NASA JPL's DE442 ephemeris, and the model only interprets those computed placements. It never calculates positions itself.
