Retrograde Planets by Birth Decade, the 1800s to the 2020s

No planet ever reverses along its orbit. Retrograde motion is how the sky looks from a moving platform: Earth circles the Sun faster than Mars, Jupiter and everything beyond, and each time it draws level with one of them, that planet seems to slide back against the stars, the way a slower train appears to roll backward as an express overtakes it. Mercury and Venus produce the same illusion from the inside track, when they swing between Earth and the Sun. While the illusion lasts, the planet's zodiac longitude shrinks from one day to the next, and chart software marks it with an R.

This study measures how ordinary that is, checking the direction of all eight planets from Mercury to Pluto at midnight Universal Time on each of 84,006 consecutive days, the 1800s through the 2020s. On 91% of those days at least one of the eight was moving backward, and the average day had 2.3 of them retrograde. Even the decade with the most all-direct days, the 1980s, had at least one planet retrograde on 77% of its days.

The Sun and the Moon are left out because neither ever appears to back up; the planetary retrograde calendar lists this year's stations planet by planet.

Across the whole span the ranking is tidy. Pluto was retrograde on 44% of all days, Neptune on 43%, Uranus on 41%, Saturn on 37% and Jupiter on 30%. Mercury follows at 19%, then Mars at 9.5% and Venus at 7.2%. Spread over a calendar, that is about 161 retrograde days a year for Pluto against 26 for Venus.

Distance sets the order beyond Earth. A far planet barely advances along its own orbit in the months Earth needs to sweep past it, so Earth's motion dominates and the backward phase fills a little under half the year, which is where Pluto and Neptune both land. Jupiter, the nearest of the five slow planets, advances fast enough to trail them. Mars is nearer again: Earth overtakes it only about every other year, and its backward phase is brief, which leaves it close to the bottom of the list.

Mercury and Venus follow a different rule, since they turn back only around the weeks when they pass between Earth and the Sun. Mercury makes that pass three or four times a year and collects about 70 retrograde days a year as a result. Venus makes it less often than once a year and reverses for only a few weeks, so it finishes last; the Mercury retrograde calendar shows how Mercury's passes fall within one year.

Counted in days, Mercury is the steadiest planet in the data. Its lowest decade, the 1840s, still gave it 69 retrograde days a year, and its highest, the 1990s, only 71. With several retrograde phases a year, every ten-year window catches nearly the same number.

Venus jumps between two levels. In most decades it was retrograde on about 6.9% of days; in the 1830s, 1870s, 1910s, 1950s and 1990s the figure rose to about 8.1%. Venus completes five retrograde phases every eight years, so forty years hold a whole number of those cycles, and the decade that picks up an extra phase comes around every fourth time. The 2020s fall between the two levels, at 7.4%.

Mars has the widest swing relative to its own size: retrograde on 7.7% of days in the 1970s and 11% in the 1990s, a factor of 1.4. Since Mars reverses only about every other year, and its phases differ in length, a decade holds a handful of them; one more or one fewer, or one split at the decade line, moves the total by whole points.

The slow planets hold closer to their long-run figures in proportion. Neptune never left the band from 42% to 44%, and Jupiter, Uranus and Pluto each varied by a smaller fraction of their size than Venus or Mars did. Saturn moved the most in points, from 33% in the 1940s to 38% in the 1810s. That is the Mars arithmetic with longer phases: each of Saturn's lasts more than four months, so one more or one fewer in a decade shifts its share by several points, though in proportion the swing is still smaller than for Venus or Mars. Pluto drifted rather than swung: about 165 retrograde days a year in the 1830s, 155 in the 1960s, back up to 163 in the 2020s. Its orbit is the most elongated of the eight, so over generations its distance from the Sun and its pace along the zodiac change, and the length of each retrograde phase changes with them.

Counting all eight at once, exactly two were retrograde on 27% of days, more than any other count. Three came next at 24%, then one at 21%, four at 14%, none at 8.9% and five at 4.8%. Somewhere between one and three were reversing on 72% of days.

The top of the scale is thin. Six planets were retrograde together on 0.9% of days, and seven on 67 days in total, every one of them in the 1820s, 1840s, 1880s, 1940s or 1980s; the 1880s alone supplied 21. On no day did all eight turn back together. That would need Venus and Mars, the two least often reversed, backing up alongside Mercury and all five slow planets at once, and the combination never came up.

A decade's average says little about its spread. The 1920s and the 1980s both averaged 2.3 retrograde planets a day, yet days with no planet retrograde made up 1% of the 1920s and 23% of the 1980s, and days with six made up 0.1% and 6.7%. Each slow planet is retrograde for the months around the date it stands opposite the Sun. When the five are scattered around the zodiac, those months fall at different times of year, so one of them is nearly always reversing; when they sit close together, they turn back as a group and go direct as a group, piling days up at both ends of the count.

Days with no retrograde planet made up 8.9% of the period, about one day in 11, or 7,490 days altogether. By decade the share runs from 1% in the 1920s to 23% in the 1980s, a ratio of about 24 to one.

The longest unbroken run began on February 11, 1844 and ended on May 17, 1844: 97 days with every planet moving forward at each midnight check. The best in any other decade was 94 days from March 20, 1855, then 90 days from December 17, 1820. At the short end, the best the 1900s and the 1930s could manage was 22 days each.

The 2020s produced their longest run in 2023: 89 days from January 23 to April 21, 2023. That equaled the run of September 25, 1983 to December 22, 1983, and no stretch starting after the 1850s has lasted longer. Charts cast for the weeks inside either window show no retrograde planet at all.

Astrologers who give weight to retrograde planets tend to start with the personal ones. Modern Western practice commonly treats a retrograde Mercury, Venus or Mars as that planet's work turned inward or run on its own timetable, and traditional texts count retrograde motion among the accidental debilities that weaken a planet. The base rates put those readings in proportion: a retrograde Mercury appears in about one chart in 5, a retrograde Mars in about one chart in 11 and a retrograde Venus in about one chart in 14.

The slow planets are another matter. Uranus, Neptune and Pluto are each retrograde on between 41% and 44% of days, and each stays that way for months, so whole seasons of births share it. Many practitioners therefore treat an outer-planet retrograde as a generational backdrop and reserve closer reading for the three planets whose shares are smallest.

Birth decade moves some of these figures far more than others. A retrograde Mars appears in about one chart in 9 for births in the 1990s and about one chart in 13 for the 1970s. Charts with no retrograde planet at all range from about one chart in 100 for 1920s births to about one chart in 4 for 1980s births, against about one chart in 11 over the full span, while five or more retrograde planets occur in about one chart in 17.

These shares rest on one check at midnight. On a day when a planet stands still before reversing, the hour of birth decides which way a chart marks it, so check a particular chart in the birth chart calculator.

Each row gives a decade's retrograde share for every planet, its share of days with none and its longest all-direct run; the last row holds the whole-period figures. A decade runs from a year ending in 0 through the next year ending in 9. The 2020s row is already complete, since planetary motion can be calculated in advance, so part of it covers days still to come.

Positions are geocentric, measured along the tropical zodiac, from precise astronomical calculations at arc-second precision, the same ones behind every chart on this site (about the site). A planet counts as retrograde when its longitude is decreasing at midnight Universal Time; one that changes direction during a day is classed by its motion at that midnight alone.

Each decade's shares are counts of days divided by that decade's length, 3,652 or 3,653 days depending on leap years, and the whole-period figures divide by all 84,006. The shares describe the sky, not any group of people; no birth records enter the study. An all-direct run belongs to the decade in which it started. The data was generated on October 13, 2026.