What changes when the house-system setting changes?
The boundaries change. Keep the time, location, zodiac and planetary longitudes fixed and a planet can receive a different house number because the divisions have moved around it. A sign stellium remains the same in this controlled comparison; a house stellium may gain members, lose members or shift emphasis.
That is a settings-dependent classification, not evidence that a planet vanished or your biography changed. Before comparing interpretations, compare the actual membership lists.
“Multiple planets move entire houses”
“Multiple planets move entire houses when I use whole or equal house.”
r/AskAstrologers · October 21, 2019
Save both charts and check the house-system label first. If every other input matches, locate each changed planet relative to the two sets of cusps. This directly explains the changed label; choosing whichever personality description feels familiar does not verify the calculation.
The discussion also mentions Placidus. Our controlled comparison below covers only Ascendant-based Equal houses and Whole Sign. It does not calculate Placidus or claim to resolve every system disagreement.
A controlled comparison with real calculated positions
Use March 4, 1990, 18:20 UTC, latitude 40.7128° north and longitude 74.0060° west. This is a constructed test case using real ephemeris calculations, not a documented person's birth. Keep the tropical zodiac and all ten bodies from Sun through Pluto fixed.
The computed Ascendant is 111.549° ecliptic longitude, or 21.549° Cancer. Equal houses start at that degree and repeat every 30°. Whole Sign puts all of Cancer in the first house, so its seventh house is all of Capricorn.
| Body | Longitude | Equal house | Whole Sign house |
|---|---|---|---|
| Sun | 343.915° | 8 | 9 |
| Moon | 82.687° | 12 | 12 |
| Mercury | 331.780° | 8 | 9 |
| Venus | 300.710° | 7 | 8 |
| Mars | 294.908° | 7 | 7 |
| Jupiter | 90.914° | 12 | 1 |
| Saturn | 292.455° | 7 | 7 |
| Uranus | 278.906° | 6 | 7 |
| Neptune | 284.078° | 6 | 7 |
| Pluto | 227.734° | 4 | 5 |
Original calculation with Astronomy Engine 2.1.19 and explicitly implemented house-boundary formulas. Values are rounded for display. These are model outputs for the stated test instant; no personal birth record was supplied or inferred.
Follow Venus through the two boundaries
Equal's seventh house extends from 291.549° to 321.549°. Venus at 300.710° falls inside it. Whole Sign's seventh extends from 270° to 300°; Venus is just beyond that endpoint and belongs to its eighth house. Uranus and Neptune take the opposite route: their Capricorn longitudes fall before Equal's seventh cusp, so they are in Equal's sixth but Whole Sign's seventh.
Mars and Saturn remain in the seventh under both methods. Their shared membership is a useful stable core for this comparison. Venus, Uranus and Neptune are the system-sensitive members. Listing both sets is more informative than announcing that one app says “yes” and another says “no.”
Now apply one threshold to both lists
The threshold is held constant within each comparison. Do not compare Equal with a four-body cutoff against Whole Sign with a three-body cutoff and attribute the difference entirely to houses. That changes two variables at once.
For another chart, write a three-column ledger: stable members, members only in system A, members only in system B. Then repeat the count. This ledger and the ten-body table are the original audit method contributed here.
Reject “the chart with the larger stellium must be more accurate”
A larger group is a consequence of the selected boundaries and rule. It is not a measurement of the system's truth. This test demonstrates where the arithmetic diverges; it cannot prove which interpretive tradition best describes a life.
It also cannot validate a guessed birth time. If the time or place is uncertain, first establish what the input can support. Our detector withholds automatic house conclusions when inputs or cusp membership are unresolved. A pleasing interpretation is not a substitute for that check.
Before comparing your own charts
Can I compare the systems in the existing detector?
Birth mode calculates Equal houses. For Whole Sign, use manual mode with verified placements from a chart explicitly labeled Whole Sign. Label that system and keep the same included bodies and threshold. The detector counts manual entries; it does not independently verify them.
Why is my sign stellium unchanged?
House boundaries do not alter tropical planetary longitudes. In this case Mars, Saturn, Uranus and Neptune remain in Capricorn in both versions. Changing from tropical to sidereal would be another setting change and is outside this comparison.
Can I combine the largest group from each chart?
You may compare interpretations, but do not merge house assignments into a single calculated chart. Save separate labeled outputs so every claim can be traced to one consistent system.
Continue with the seventh-house guide, Capricorn guide, or all stellium guides.
Method and sources
Astrodienst's Equal House reference describes thirty-degree divisions anchored to the Ascendant degree and distinguishes Whole Sign's sign-boundary origin. Astronomy Engine supplies the celestial positions and sidereal-time quantities. The public reader question is linked above.
The computed comparison, stable-member ledger, threshold comparison and two diagrams are original to this page. Astrology's interpretive claims are not scientifically established predictions.