How to Calculate Your Secondary Progressions (Step by Step)

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This page is the working method. It turns your age into a progressed date, reads the planets for that date from an ephemeris, and lines them up against your natal chart. What the results may mean is covered on secondary progressions explained and the progressed Moon.

You will be reading an ephemeris for a date a few weeks after your birth, not for today. That is the difference from transit work, where the ephemeris date is the real date you are interested in (see the transits overview). Progressions are a separate symbolic technique, so keep the two sets of positions apart on paper.

Do-it-yourself method. Astrologist.com does not calculate progressions: the free birth chart gives natal positions only, and there is no progressed chart, timeline or report. The example figures here were calculated offline with the same routines that produce the free chart, so they are a check on your arithmetic, not a hidden feature.

You need your natal chart, a Tropical geocentric ephemeris (a public table of daily planet positions, usually given for 00:00 UT), your birth time and about twenty minutes.

Step 1: write your birth instant in UT

Ephemerides are tabulated in Universal Time, so convert your local birth time first, allowing for the time zone and any daylight saving in force that day. Birth time, time zones and daylight saving explains how. A London birth in January needs no change, because UK winter time equals UT.

Step 2: turn your age into a progressed date

For a whole-number age, add that many days to your birth date and keep the same UT clock time. Age 33 means 33 days after birth, at the birth time in UT.

For a date between birthdays, this page uses one interpolation convention: count the days of life elapsed since birth, divide by 365.2422 to get your age in years with a fraction, and add that many days (fraction included) to the birth instant. Three months past a birthday is about a quarter of a day, roughly six hours of ephemeris time. That is this page's working method; other astrologers handle the fraction a little differently.

Step 3: read the positions for that instant

Find the progressed date in the ephemeris. If your UT birth time is not 00:00, interpolate between that day's row and the next one: take the fraction of the day (UT hours divided by 24) of the difference between the two rows and add it. Do this for the ten planets from the Sun to Pluto. The Moon needs the most care, because it moves 12° to 15° between rows.

A cross-check is possible with the free chart itself, which takes local civil clock time. Keep the progressed instant in UT, convert that UT clock time to the local civil time in force at your birthplace on the progressed date, and enter that date, that local time and your birthplace. Do not simply reuse your local birth time: if the time-zone or daylight-saving offset on the progressed date differs from the one at birth, the positions come out an hour wrong. Use only the planet table. Its Ascendant, Midheaven, houses and aspect list belong to that other date and are not progressed angles or progressed aspects under this method.

Step 4: note what changed

For each planet, compare the progressed position with the natal one. Note sign changes, and any planet that has turned retrograde or direct since birth. Mercury, Venus and Mars are the ones to watch; Jupiter to Pluto will have moved little.

Step 5: list the progressed-to-natal contacts

Check each progressed planet against each natal planet for the five major aspects: 0°, 60°, 90°, 120° and 180°. Write down the exact distance from the aspect for anything close. Many astrologers use an orb of about 1° or less for progressions, but that is a convention with variation between authors, not an Astrologist.com rule, and it is not the 8° and 6° natal orbs. Keep contacts between a progressed planet and its own natal position on the list too: they are legitimate progression events, and the progressed lunar return described on the progressed Moon page is one of them. Jupiter to Pluto stay near their natal degrees for many years, so a slow planet that is close to, but not exactly on, its own natal degree can be noted separately as background rather than ranked with the other contacts. If you want the date a contact becomes exact, repeat Step 3 for nearby dates until the distance reaches zero.

Step 6: place the progressed planets in your natal houses

Only with a reliable birth time. Use your natal cusps and settle anything near a cusp with the degrees, as in how to find your house cusps. This is a natal-house overlay; no progressed house cusps or progressed angles are calculated.

Step 7: test the birth time

Run Steps 1 to 6 again for a birth time an hour earlier and an hour later. For each candidate time, recompute both sides of the comparison: the natal chart for that time (planet positions, especially the Moon, and the natal house cusps) and the progressed instant and positions derived from that same candidate birth instant. If a contact or house placement changes, mark it as time-sensitive. With no birth time at all, run 00:00 and 23:59 and skip houses. Those two runs illustrate the endpoints only and do not prove what happens across the whole birth date; if a conclusion depends on something holding all day, check intermediate times and any planet station in that span instead of inferring it from the two ends. How accurate does your birth time need to be? and how to read a chart without a birth time cover what survives.

Worked example: Ruben at 33

Ruben is the fictional example used in several Astrologist.com guides: London, 5 January 1993, 12:00, which is 12:00 UT. The age was fixed at exactly 33, his birthday on 5 January 2026, before any result was looked at. Progressed instant: 5 January plus 33 days, which is 7 February 1993 at 12:00 UT.

Natal and progressed positions

Placidus natal houses, Ascendant 3°46' Taurus. What changed: the Sun, Mercury and Venus have each changed sign once; progressed Mars is still retrograde and has backed into the 3rd house; progressed Jupiter turned retrograde at about 23½; the Moon is on its second lap of the zodiac.

Contacts at the age-33 instant

None of the five major aspects is exact at that instant. With an illustrative window of ±1°, used here for teaching and not as the site's orb:

• Progressed Venus square natal Mercury, 0.12° short of exact and closing. It perfects at age 33.14, late February 2026.
• Progressed Jupiter square natal Sun, 0.62° wide. It never becomes exact: progressed Jupiter came within 0.49° when it turned retrograde at about 23½ and is now moving away.
• Progressed Jupiter and progressed Pluto are each within 1° of their own natal degree. Neither is exact, and both slow planets stay near their natal positions for a long time, so this short list notes them here as background rather than ranking them with the contacts above.

Just outside the window: the progressed Moon squared natal Pluto in December 2025 and is now 1.14° past, and the progressed Sun conjoined natal Saturn at about 31 and is now 1.9° past.

Exact contacts in his 34th year

Searching forward from the 33rd birthday with the same convention, these are the contacts that become exact before he turns 34:

Read each one as a theme coming into focus for a while, with the meaning set by the two planets involved, not as an event on a date.

Birth time: 11:00 and 13:00

Recomputing both the natal chart and the progressed positions for each time, moving the birth time an hour either way moves the progressed instant an hour too, which shifts dates by about 15 days of life, but not uniformly:

• Progressed Venus square natal Mercury: 13 February (11:00), 26 February (12:00), 11 March 2026 (13:00).
• Progressed Moon trine natal Mercury: 11 August, 29 July, 15 July 2026.
• Progressed Moon square natal Moon: 31 August, 29 August, 27 August 2026. Almost no shift, because the natal Moon it aspects moves with the birth time as well.

The houses are far more sensitive. At 11:00 every one of the ten progressed planets falls in a different natal house from the 12:00 table; at 13:00, six of the ten do. The progressed positions barely change; the natal cusps do.

Unknown birth time: 00:00 and 23:59

An endpoint illustration only, not proof of what holds at times in between: across the birth date, Ruben's progressed Moon at 33 runs from 18°15' Leo to 3°29' Virgo, so even its sign is open, and the progressed Sun runs from 18°13' to 19°14' Aquarius. Progressed Venus square natal Mercury stays inside the ±1° window at both ends. At 00:00, contacts appear that are absent at 12:00, such as progressed Mercury square natal Moon. Without a time, Ruben's progressed house placements and any contacts to his angles would not be available at all.

Next steps

For what the pieces mean, go back to secondary progressions explained for the technique and the progressed Moon for the Moon's signs, houses and cycles. The same ephemeris-and-natal-chart approach for real-sky timing is in how to read transits without a tool, and solar return date is another offline timing example. How transits work, planet meanings and the methodology page give the background. You can ask the Astrologist about positions you have worked out yourself; it does not compute progressed positions or dates.

Related articles

• Secondary Progressions Explained
• The Progressed Moon
• Birth Time, Time Zones and Daylight Saving
• How Accurate Does Your Birth Time Need to Be?
• How to Find Your House Cusps
• How to Read Transits Without a Tool