Free Astrology Tool

Transit Chart Calculator

Astrolium's free transit chart calculator returns current transits for any birth chart with interpretation: house, aspect, peak date, Swiss Ephemeris.

Birth data
30-day transit window starting today. Nothing stored.

What is Transit Chart?

The Astrolium transit chart calculator returns your current transits with full interpretation for any birth chart: outer-planet hits, ingresses, eclipses, and stations across the next 90 days. Math runs on the Swiss Ephemeris. No login, no email, no upload.

A transit chart shows where the sky is right now in relation to your natal placements. The calculator drafts a 90-day forecast you can edit and send to a client in under 10 minutes total. Prose is drafted by the AI assistant on a corpus of cited source material.

Time saved: 60 to 90 minutes per client. If you write transit reports for 10 clients a month at $150 to $300 each, that's 10 to 15 hours of writing time returned to you every month, or roughly the difference between writing as a chore and writing as a 10-minute editorial pass. This is your draft, ready to edit and ship.

The full transit reading stack with interactive chart, scrubbable timing ribbon, and batch generation across a client roster lives inside the predictive timing feature and the AI assistant feature. For the year-frame report, see the solar return reading generator. For the full natal write-up, see the natal chart report generator. For the $29 per month Pro tier with batch generation, see pricing.

What you get

The Astrolium free transit report returns a written 90-day forecast of major transits to the natal chart, with each transit's peak date, retrograde window, and interpretive paragraph drafted by the AI assistant against cited source material. Inputs are birth date, time, and place plus the start date of the forecast window; the tool runs the live ephemeris against every natal planet and angle, surfaces every Ptolemaic aspect inside the 90 days, and composes a prose document that opens with a one-paragraph cycle summary, then walks the transits in chronological order with outer planets, ingresses, and eclipses leading. Each transit paragraph names the body, the natal point activated, the exact peak date, the retrograde stations inside the window, and 3–6 sentences of practitioner-grade read. Math runs on Swiss Ephemeris, accurate to under 1 arc second; render time is under 60 seconds. Free, no account required.

The report is structured as a prose document, not a table. It opens with a one-paragraph summary of the cycle: which planets are most active, which natal placements they activate, the structural theme of the window. Then it walks transit by transit in chronological order. Outer-planet transits first, ingresses and eclipses second, faster-moving transits noted as context.

Each transit paragraph names the body, the natal point it's activating, the exact peak date, the retrograde stations inside the window, and a 3 to 6 sentence read. The reads are written for a client audience: clear, specific, free of jargon, anchored in the source material so you can defend any claim a client questions.

Why this reads as a draft

The framing matters. Astrolium isn't replacing you. It's handing you a structured first pass so you spend your time on editorial judgment instead of typing.

The AI gets the math right. The AI cites its sources. The AI writes serviceable prose. What the AI cannot do is know which transit matters most to this client, which framing will land, which clause needs to be softened because the client just lost a parent. That's your job. Astrolium's job is to get you to 85% in 60 seconds.

Most practitioners edit one or two paragraphs, tighten the opening, add the personal note, and ship the draft in under 10 minutes total. The compounding effect across a roster is the actual product.

This free tool reads from a shared source corpus. Inside Astrolium, the AI assistant reads each chart against your own Knowledge Base, the interpretation rules and notes you upload, so the forecast already follows your method and goes out as a client email, Instagram message, or PDF with little editing.

What's inside a typical report

Three layers.

Outer-planet transits: Saturn, Jupiter, Uranus, Neptune, Pluto, Chiron. These move slowly enough to define the structural theme of the cycle. A Saturn square to natal Sun inside the 90-day window dominates the report; everything else reads as ornament around it. Astrolium surfaces these first. If the window contains a Saturn return, use the Saturn return calculator to see the triple-pass dates alongside this report.

Eclipses and ingresses: the moments inside the window when a planet changes sign, an eclipse falls on a natal placement, or a station reverses direction. These are dated to the day and paragraphed individually.

Faster transits as context: Mars, Venus, Mercury, the Moon's monthly cycle. Astrolium doesn't paragraph each one. It flags the cases where a faster transit will activate the outer-planet picture on a specific date. A Mars trigger to a Saturn return, for example, often pinpoints the felt moment inside the longer Saturn season.

The AI corpus

Every interpretive claim is traceable. The corpus includes Robert Hand's Planets in Transit, Howard Sasportas's The Gods of Change, the Hellenistic source material Chris Brennan documented in Hellenistic Astrology, and a curated set of modern practitioner texts. Each paragraph cites which source the reading leans on, so you can verify and adjust without re-deriving from scratch.

For the corpus list and the way Astrolium trains the assistant, see the AI assistant feature. For the broader question of where AI fits in client work, see the AI in astrology guide.

How the math runs

Swiss Ephemeris DE431, the same kernel Solar Fire and Astro Gold use. Transit positions match to the arc-second. Peak dates are computed to the second. Retrograde station dates are bracketed exactly.

The report window defaults to 90 days but accepts 30, 60, 90, or 180. The longer the window, the more outer-planet content. Astrolium supports 5 house systems (Placidus, Whole Sign, Porphyry, Equal, Koch), switchable from the dropdown. Whole-sign houses are recommended if you want the report to lean Hellenistic; Placidus is the modern Western default.

Nothing is stored. Nothing is emailed. The draft renders in your browser and disappears when you close the tab. The Pro tier offers persistent storage and batch generation; the free tier runs ephemeral.

After the report

A transit report reads inside the larger predictive picture. The same 90-day window also contains a profected year, a Zodiacal Releasing period, a Solar Return chart, and possibly a Saturn or Venus return. The transits are the moving plot; the time-lord techniques set the protagonist.

For the integrated view where transits stack against profections and ZR on one scrubbable ribbon, see the predictive timing feature. For the year-frame report, see the solar return reading generator. For the foundational read of the chart the transits are hitting, see the natal chart report generator.

Cross-link

Pair this with the natal chart report and the solar return reading for a full three-document client packet. For the timing technique that sets the year's theme, run the profections calculator. For the major return calculators that often land inside a 90-day transit window, see the Saturn return calculator, chiron return, and jupiter return. For the deeper context, see the Saturn return guide and the hellenistic astrology guide.

Related

Frequently asked questions

What is a transit chart?
A transit chart shows where the planets are right now (or on any chosen date) plotted against your natal chart. It's the standard tool for current-moment astrology: which transiting planets are aspecting your natal placements, which houses are activated, when the contacts perfect. The Astrolium transit chart calculator builds the chart from Swiss Ephemeris positions and writes interpretive paragraphs for each significant transit in the window.
How long does the draft save me per client?
Most practitioners report 60 to 90 minutes saved per transit report. Astrolium drafts the 90-day forecast in 60 seconds; you spend 5 to 10 minutes editing the two or three paragraphs that matter most and shipping it. The compounding effect across a roster of 10 to 15 monthly clients is 10 to 15 hours of writing time returned per month.
What's inside the transit report?
A written 90-day forecast covering the major transits to your natal chart: Saturn, Jupiter, Uranus, Neptune, Pluto, Chiron, plus eclipses and ingresses inside the window. Each transit gets a paragraph: what it means, when it's exact, what to watch for. Astrolium drafts the prose with the AI assistant trained on traditional and modern source material, sources cited inline.
Is this a finished client deliverable?
No. It's a draft. Astrolium's framing is that the AI hands you a structured first pass with accurate math, defensible interpretation, traceable sources, and you bring the editorial judgment. Most practitioners edit one or two paragraphs and ship. The AI gets you to 85% in 60 seconds; you bring the 15% that's yours.
How accurate is the AI interpretation?
The transit math is exact: Swiss Ephemeris, arc-second positions, peak dates within seconds. The interpretive prose is drafted against a corpus that includes Robert Hand's Planets in Transit, Howard Sasportas's The Gods of Change, and the Hellenistic source material Chris Brennan documented. Every claim is traceable to a source you can cite. See the AI assistant feature for the full corpus list.
Can I generate this for clients without uploading their data?
Yes. The free transit report runs in your browser: no signup, no upload, no data retention. The $29 per month Pro tier adds batch report generation, so you can drop a roster CSV and Astrolium returns one draft transit report per client, sorted by report intensity.

Want this inside your client roster?

Run the calculator above for a one-off chart, or save every chart you cast to a client profile in Astrolium.