Whole sign, equal and Placidus houses
Astra product guide · Updated
Whole sign divides the zodiac into houses starting at the beginning of the Ascendant's sign. Equal houses start at the exact Ascendant degree, with equal-sized divisions. Placidus uses time-based divisions and can produce unequal house sizes. In Astra, changing the house system leaves planetary longitudes unchanged but can change their house assignments.
Compare the same birth data
Reproduce this example: 1990-11-02, 04:30 (Europe/Madrid), Barcelona, 41.38879°, 2.15899°. The public Sofia sample is demonstration data, not a customer record. Its calculated instant is . The tables round positions to two decimal places; calculations use unrounded values.
Each table is calculated by Astra's current engine from those inputs. The Ascendant and Midheaven stay the same across systems. The first house begins at the Ascendant's sign boundary in whole sign, and at the Ascendant degree in equal and Placidus. The Midheaven need not be the tenth-house cusp in whole sign or equal.
On a narrow screen, scroll each table sideways to compare all three systems.
| House | Whole sign | Equal | Placidus |
|---|---|---|---|
| 1 | Libra 0.00° | Libra 4.58° | Libra 4.58° |
| 2 | Scorpio 0.00° | Scorpio 4.58° | Scorpio 0.88° |
| 3 | Sagittarius 0.00° | Sagittarius 4.58° | Sagittarius 1.53° |
| 4 | Capricorn 0.00° | Capricorn 4.58° | Capricorn 5.34° |
| 5 | Aquarius 0.00° | Aquarius 4.58° | Aquarius 8.94° |
| 6 | Pisces 0.00° | Pisces 4.58° | Pisces 9.06° |
| 7 | Aries 0.00° | Aries 4.58° | Aries 4.58° |
| 8 | Taurus 0.00° | Taurus 4.58° | Taurus 0.88° |
| 9 | Gemini 0.00° | Gemini 4.58° | Gemini 1.53° |
| 10 | Cancer 0.00° | Cancer 4.58° | Cancer 5.34° |
| 11 | Leo 0.00° | Leo 4.58° | Leo 8.94° |
| 12 | Virgo 0.00° | Virgo 4.58° | Virgo 9.06° |
| Planet | Whole sign | Equal | Placidus |
|---|---|---|---|
| Sun | 2 | 2 | 2 |
| Moon | 7 | 7 | 7 |
| Mercury | 2 | 2 | 2 |
| Venus | 2 | 2 | 2 |
| Mars | 9 | 9 | 9 |
| Jupiter | 11 | 11 | 11 |
| Saturn | 4 | 4 | 4 |
| Uranus | 4 | 4 | 4 |
| Neptune | 4 | 4 | 4 |
| Pluto | 2 | 2 | 2 |
Which should I choose?
Use the system required by the learning material or practitioner you are following, and record the choice when comparing charts. A change in house assignment is a consequence of the definition of a house; this comparison does not establish that one system predicts life events more accurately.
When Astra cannot calculate Placidus
Astra rejects Placidus at latitudes of 66° north or south and beyond. Choose whole sign or equal for those inputs. If your birth time is unknown, Astra omits all house systems and angles instead of assigning houses from a guessed time. See the unknown-time example.
Continue with your chart
Explore the calculated sample without an account, or sign up and confirm your email to save your own chart. Treat interpretations as reflection, with the limits of your inputs in mind.