What a transit is
A transit is simply where a planet is now, measured against where it stood when you were born. Saturn is somewhere in the sky today; if that somewhere happens to be the exact degree your natal Sun occupies, Saturn is transiting your Sun.
Nothing about that is metaphorical at the point of calculation. It is a comparison between two sets of coordinates, and the entire interpretive tradition is built on top of that comparison.
Because the planets move at wildly different speeds, transits divide naturally into two kinds. The Moon crosses your whole chart every month and the effects, if any, last hours. Pluto takes a decade or more to cross a single house. Those are not the same phenomenon and should not be read the same way.
The orb is the whole story
Every transit has a period during which it is approaching, a moment of exactness, and a period of separating. The orb, the distance from exact, tells you where in that arc you currently are.
A transit at three degrees is background. At one degree it is the loudest thing in the chart. The calculator sorts by orb for that reason and separates the contacts inside one degree from the rest, because a list of thirty transits with no ordering is worse than no list at all.
| Transiting body | Typical time within one degree |
|---|---|
| Moon | About two hours |
| Sun, Mercury, Venus | Two to four days |
| Mars | Up to a week, longer if retrograde |
| Jupiter | A few weeks, three times if retrograde |
| Saturn | Several weeks, usually three passes |
| Uranus, Neptune, Pluto | Months, and up to three separate passes |
Retrograde passes, and why a transit repeats
Outer planets appear to reverse direction for part of each year. When one turns retrograde near a natal degree, it crosses that degree three times: forward, back, and forward again, usually spread across nine to fourteen months.
Traditional practice reads the three passes as one long event rather than three separate ones. The first pass raises the issue, the retrograde pass is where it is worked over, and the third pass is where it settles. That structure is genuinely useful for planning, and it is the reason a Saturn transit rarely feels like a single day.
The calculator shows you the current orb on any date you choose, so entering a few dates across a year will show you the shape of a slow transit rather than a snapshot of it.
Which house the transit is crossing
The result lists which of your houses each transiting planet currently occupies, and that is often more informative than the aspects. A planet crossing your seventh house is working on partnership whether or not it makes an exact aspect to anything.
House transits are the slow structural layer. Saturn spends two to three years in a house, and people describe those periods far more consistently than they describe individual aspects. If you want one thing from a transit reading, take which house the outer planets are currently in.
This requires a birth time, since houses do. Without one, the aspects still work and the house column is blank rather than guessed.
What transits do not do
They do not predict events. A transit describes a condition and a pressure, and two people under the same transit can spend it entirely differently. Any tool that tells you what will happen on a date is inventing the specific part.
They also do not distinguish good from bad reliably. Jupiter transits are conventionally fortunate and routinely coincide with overreach; Saturn transits are conventionally difficult and routinely coincide with the most durable work someone does. The tone of a transit is a poor guide to its usefulness.
What they do reasonably well is describe timing: when a theme is live, roughly how long it lasts, and when it recurs. That is a modest claim and it is the honest one.
Reading today, and reading a year
For a single date, look at the contacts inside one degree and ignore the rest. Usually there are between one and four, and they are what today is made of astrologically.
For a longer view, the slow transits matter and the fast ones do not. Enter dates a month apart across a year and watch which outer-planet contacts appear, tighten and separate. That is a more honest year-ahead reading than any single chart, and it costs nothing.
For a dated structure rather than a scan, the solar return chart and the return calculators give exact moments rather than approximate windows.
Common questions
What is a transit?
Where a planet is now, measured against where it stood at your birth. Nothing more mysterious than a comparison between two sets of coordinates; the interpretation is built on top of that.
How tight does a transit need to be to matter?
Inside one degree it is the loudest thing in the chart. At three degrees it is background. The list is sorted by orb and separates the close contacts for that reason.
Why does the same transit happen three times?
Because outer planets turn retrograde. When one reverses near a natal degree it crosses that degree forward, back and forward again, usually across nine to fourteen months, and the whole passage is read as one event.
Can transits predict what will happen?
No. They describe a condition and a pressure, and two people under the same transit can spend it entirely differently. Any tool naming an event on a date has invented the specific part.
Do I need a birth time for transits?
For the aspects, no. For which of your houses a planet is crossing, yes, and that house information is often the more useful half.
Which transits are worth watching?
The slow ones. Moon transits last hours and Sun transits days; Saturn, Uranus, Neptune and Pluto contacts last months and are the ones people describe consistently.