Transit chart calculator

Give your birth details and a moment to read — now, or any date you like — and you get the moving sky laid over your chart: which of your houses each planet is crossing, every contact it is making, and a timeline of the exact dates ahead. Free, no account, nothing stored.

What it does, and why it is here

A transit is where a planet is today against where it was when you were born. Nothing in that sentence is a lookup: it needs the current ephemeris, your natal positions, and your house cusps, which means casting your birth chart first and then measuring the second sky against it.

Two things make it awkward to do by hand, and both are why this page exists. The first is that the house matters more than the sign: Saturn in Pisces is a fact about the year and true for everyone alive, while Saturn crossing your sixth house is a fact about you — and only your birth time and place decide which house that is.

The second is timing. A slow planet does not touch a natal point once. It comes forward, turns retrograde, crosses back, then goes direct and crosses a third time, so what feels like one long episode is three exact dates spread over months. Reading that off a single chart is impossible; it needs a timeline, which is what the tool computes.

What you fill in

• Date and time of birth and city — the natal chart the transits are measured against. The city fixes both the coordinates and the historical time zone.
• Moment to read — leave it empty for now. A future date is perfectly normal here; that is what transits are usually asked about. It is read in your birth place’s time zone.
• Look ahead — 30 or 90 days, deciding how far the timeline of exact contacts runs from that moment.
• House system — Placidus, Koch, equal or whole sign. It changes which house a transit falls in, so it changes the reading; the answer states the one it used.

What you get back

• What the moving sky is touching — every current contact, with the transiting body, the aspect, the natal point it hits, the orb, and which of your houses it falls in.
• Where the planets are, in your houses — the whole sky placed in your chart, not just the bodies making aspects. This is the background reading: which areas of the chart are busy at all.
• Coming up — the timeline of exact contacts over your chosen horizon, with dates. This is what turns “Saturn is squaring my Sun” into “on these three days”.
• Planetary returns — when a planet comes back to the degree it held at your birth. The Saturn return around 29 and the Jupiter return every twelve years are the ones people come looking for.
• The Moon today, given separately, because it moves through a sign in two and a half days and belongs on a different clock from the rest.
• Your birth chart, for reference, underneath — so you can check the natal positions the transits are being measured against without opening a second tool.
• And when nothing is in range, it says so plainly and suggests a date a few weeks out, rather than padding the table with contacts too loose to mean anything.

What it does not do

It does not interpret, and it does not predict. It tells you which planet is at which angle to which point of your chart, on which dates. What that means is a reading, and a reading is a person’s job.

It does not keep your birth details: they are used to cast the chart and then forgotten, never stored and never put in a link.

And it lists only what is genuinely close. A loose orb turns any date into a wall of contacts, which is the fastest way to make a transit list meaningless.

The cycles, and how long each one lasts

Which transits are worth watching depends entirely on how fast the planet moves.

The bottom two rows are why the timeline exists. A Saturn contact that is exact in March, again in July and again in December is one transit seen three times, not three separate events — and the middle pass is the retrograde one.

Questions

Is this calculator free?

Yes. No account, no e-mail, no limit.

Do you store my birth details?

No — used to compute, then forgotten.

Do I need my exact birth time?

For the houses, yes: without it the transits are still correct against your planets, but “which house” has no answer, and that is half of what a transit reading is.

Can I look at a future date?

Yes, and that is the usual reason to be here. Put the date in the moment field and the whole answer, timeline included, is computed from there.

Why does the same transit appear on three different dates?

Because the planet crosses the point going forward, again while retrograde, and a third time going forward once more. One transit, three exact passes, spread over months for the slow planets.

What is a planetary return?

The moment a planet comes back to the exact degree it occupied at your birth. Saturn does it at about 29 and again near 58; Jupiter every twelve years. The answer lists the ones ahead of you.

Why does it ask for a city rather than coordinates?

Because the city also carries the time zone your birth time was recorded in, historical daylight saving included — which is the commonest reason two charts of the same person disagree.

Which house system should I use?

Whichever your natal chart uses, so the two agree. Placidus if you have no preference.

Sources and further reading

• Transits — the technique and its vocabulary.
• Apparent retrograde motion — why a contact happens three times.
• Aspects and orbs — what counts as close enough.