What a dominant planet is
Every birth chart has all ten planets, but they don't all speak equally loud. The dominant planet is the one that stands out: it rules your rising sign or your Sun sign, sits right on the horizon or the meridian, is at home in its sign, or is tied into the rest of the chart by many close aspects. Astrologers read its themes as a thread through your whole personality. A Libra with a dominant Mars, for instance, is read as far more direct and competitive than Libra alone suggests.
There is no single official way to find it, and astrologers weigh the factors differently. This calculator uses one clear point system and shows every point, so you can see the reasoning and weigh it yourself.
How the score works
| Factor | Points |
|---|---|
| Rules your rising sign (your chart ruler) | 6, or 3 for a traditional co-ruler |
| Rules your Sun sign | 3, or 1.5 for a traditional co-ruler |
| Rules your Moon sign | 3, or 1.5 for a traditional co-ruler |
| Within 8° of the Ascendant or Midheaven | 6 |
| Within 8° of the Descendant or IC | 4 |
| Otherwise in an angular house (1st, 4th, 7th, 10th) | 2 |
| Otherwise in a succedent house (2nd, 5th, 8th, 11th) | 1 |
| In its own sign (domicile) | 4 |
| In its exaltation | 3 |
| Each major aspect to another planet, the Ascendant or the Midheaven | 1, and 1 more within 2° |
| Final dispositor | 4 |
The rulers of the rising, Sun and Moon signs are the modern ones, Pluto for Scorpio, Uranus for Aquarius and Neptune for Pisces, with the older ruler of those signs (Mars, Saturn and Jupiter) given half. Dignity and the final dispositor follow the traditional scheme of the seven classical planets, the Sun to Saturn. That is deliberate: Uranus, Neptune and Pluto stay in one sign for years, so a point for being in their own sign would go to everyone born in those years. The outer planets can still lead a chart through the angles, the houses, their aspects and the signs they rule. The share beside each planet is its part of all the points in the chart.
How to find a final dispositor
A planet's dispositor is the ruler of the sign it occupies. Follow that ruler to the ruler of its own sign, and keep going. The result above lets you start with any planet and inspect each step.
For example, Venus in Aries leads to Mars. If Mars is in Leo, continue to the Sun. If the Sun is in Leo too, that chain ends there: the Sun rules its own sign. The Sun is the single final dispositor only if every other planet's chain also ends there.
The calculator uses traditional sign rulership: Mars for Scorpio, Saturn for Aquarius and Jupiter for Pisces. All ten planets have chains, including the outer three. A pair in each other's signs is mutual reception by sign; three or more planets can also loop. Separate ends and loops mean there is no single final dispositor under this method. Modern rulership can give a different answer.
See Astrodienst's explanations of dispositors and dispositor chains. These are astrological conventions. A final dispositor receives four points here, so it need not be your highest-scoring dominant planet.
Your strongest element and modality
The calculator also weighs which elements and modalities your chart leans toward. Not every placement counts the same: the Sun, the Moon and the Ascendant count 4 each, Mercury, Venus and Mars 2, Jupiter and Saturn 1, Uranus, Neptune and Pluto half a point each, and the Midheaven 1. Without a birth time the Ascendant and Midheaven are left out. The birth chart shows the plain count of planets in each element; this weighting follows how much each placement is usually read to matter.
- Fire (Aries, Leo, Sagittarius): enthusiasm, courage and action.
- Earth (Taurus, Virgo, Capricorn): practical sense, patience and the material world.
- Air (Gemini, Libra, Aquarius): ideas, conversation and connection.
- Water (Cancer, Scorpio, Pisces): feeling, intuition and attachment.
The modalities describe how that energy moves. Cardinal signs start things, fixed signs keep them going and mutable signs adapt and change them. The sign that pairs your strongest element with your strongest modality is your signature sign. When two elements or modalities tie, more than one sign fits, and the calculator gives each.
Dominant planet, chart ruler and stellium
These three are often confused. Your chart ruler is simply the planet that rules your rising sign. Ruling the rising sign is worth 6 points, tied for the most of any single factor, yet the chart ruler led only 45% of the 3,000 sample charts. A stellium is three or more planets gathered in one sign or house, a crowd that shows where the chart's energy goes. Your dominant planet weighs all of it together, with your Sun, Moon and rising signs.
How it is worked out
The planets and angles come from the site's own ephemeris, the same one behind every chart here, and the houses follow the house system chosen in the chart settings (Placidus by default). Aspects use the same orbs as the birth chart: 8° for conjunctions and oppositions, 7° for trines and squares and 5° for sextiles, 2° wider when the Sun or Moon is involved and 2° narrower to the Ascendant or Midheaven. Your details stay in your browser.