Tri-wheel chart
The tri-wheel is one of the views astrologers use most when they read a period of life. The inner ring holds your birth chart, the middle ring your secondary progressions and the outer ring the sky of the day you choose, that is, the transits. With the three layers on one wheel you can see at a glance what is moving in your life and within you.
Progressions describe your slowly unfolding inner development: each day after your birth stands for one year of your life. Transits show influences that come from outside, events and the mood of the period. When a progression and a transit touch the same point of your birth chart at the same time, that matter is ripening both inside and outside; such meetings are often seen at the important turning points of life.
If you leave the date empty, today's chart is drawn. You can enter the date of a past event to see what triggered it, or a future date to see what you are preparing for.
How is it calculated?
The inner ring is your birth chart, calculated from your birth date, time and place; the houses use the Placidus system. The middle ring is the secondary progression: each day after your birth counts as one year, and the planetary positions of the day corresponding to the date you choose are taken. The progressed Ascendant and Midheaven are advanced by the solar arc method. The outer ring is the sky at noon on the date you choose.
We use tight orbs for the aspects: 1° for progressions to the birth chart, 1° for slow transits to the progressions, and the same orbs as our transit chart for transits to the birth chart. To keep the wheel readable, only the tightest aspects are drawn as lines.
How to read a tri-wheel chart
Start reading from the middle ring: the sign and house of your progressed Sun and progressed Moon describe the current theme of your inner development. The progressed Moon changes sign roughly every two and a half years and shows how your emotional needs are shifting. Then look at the aspects your progressions make to your birth chart within 1°; these are important inner processes that last a few years.
Then move to the outer ring. The aspects of Jupiter, Saturn, Uranus, Neptune and Pluto to your birth chart describe the big outer events of the period, while the fast planets are triggers lasting a few days. The strongest periods are those in which a transit touches both a point in your birth chart and a progression that is touching the same point.
Finally, look at the houses: which houses of your birth chart the progressed and transiting planets are moving through shows in which area of your life this movement is lived.
Frequently asked questions
What is a tri-wheel chart?
It is a chart that shows your birth chart, your progressions and the transits of the day you choose in three nested rings. The inner ring is the birth chart, the middle ring the progressions and the outer ring the transits. It is used to read a period with its inner and outer influences together.
What is the difference between progressions and transits?
Transits are the actual positions of the planets in the sky and describe events that come from outside and the mood of the period. In secondary progressions each day after birth stands for one year; progressions describe slowly unfolding inner development and maturing.
Do I need my birth time for a tri-wheel chart?
Your birth date is enough for the planets, but the houses, the Ascendant and Midheaven and their progressions need your birth time and place. If the time is unknown, the chart is drawn without houses.
Which aspects matter most?
Progressions to your birth chart within 1° and transits of the slow planets (Jupiter to Pluto) matter most. If a transit touches both a point in your birth chart and a progression at the same time, that period is felt especially clearly.