How the Chaldean Order Assigns Planets to 10-Degree Decans
Starting at 0° Aries (the Vernal Equinox anchored by the Two of Wands under Mars), the 36 decans cycle continuously through the seven classical planets in descending orbital period: Saturn, Jupiter, Mars, Sun, Venus, Mercury, and Moon. If you divide 36 decans by the 7 classical planets, then the sequence completes 5 full heptads (35 decans) plus 1 final decan (36 ≡ 1 mod 7), causing both the first decan (0°–10° Aries) and last decan (20°–30° Pisces) to be ruled by Mars.
Because Mars rules both Decan 1 (Two of Wands · 0°–10° Aries) and Decan 36 (Ten of Cups · 20°–30° Pisces), traditional Hermetic astronomy views the transition from Pisces back into Aries as a double-Mars ignition point. Across each 30-degree zodiac sign, the three 10-degree decans correspond to a Cardinal, Fixed, or Mutable triad of numbered pip cards within that sign’s elemental suit.
Specifically, Cardinal signs (Aries, Cancer, Libra, Capricorn) house the Twos, Threes, and Fours of their elemental suit; Fixed signs (Taurus, Leo, Scorpio, Aquarius) house the Fives, Sixes, and Sevens; and Mutable signs (Gemini, Virgo, Sagittarius, Pisces) house the Eights, Nines, and Tens.
| Zodiac Modality | Zodiac Signs Included | Assigned Minor Arcana Ranks | Total Decan Cards | Structural Phase in Suit |
|---|---|---|---|---|
| Cardinal Signs | Aries (🜂), Cancer (🜄), Libra (🜁), Capricorn (🜃) | Twos (II), Threes (III), Fours (IV) | 12 Cards (3 × 4) | Initiation, synthesis & structural anchoring |
| Fixed Signs | Taurus (🜃), Leo (🜂), Scorpio (🜄), Aquarius (🜁) | Fives (V), Sixes (VI), Sevens (VII) | 12 Cards (3 × 4) | Stress-testing, harmonic balance & conviction |
| Mutable Signs | Gemini (🜁), Virgo (🜃), Sagittarius (🜂), Pisces (🜄) | Eights (VIII), Nines (IX), Tens (X) | 12 Cards (3 × 4) | Adaptation, autonomous culmination & completion |
Frequently Asked Questions
What is a decan in tarot and astrology?
Each 30-degree zodiac sign is divided into three 10-degree arcs called decans (or faces). Because there are 12 zodiac signs, 12 × 3 = 36 decans, which correspond 1-to-1 with the 36 numbered Minor Arcana cards from Two through Ten.
Why does the Golden Dawn use the Chaldean planetary decan system instead of triplicity decans?
Codified in Ptolemy’s Tetrabiblos and Agrippa’s Three Books of Occult Philosophy, the Chaldean planetary order (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon) assigns an individual planetary dynamic to every 10-degree arc of the ecliptic.
How do the 12 Court Knights, Queens, and Kings span the zodiac wheel?
Excluding the 4 Earth-of-Suit Pages, the remaining 12 Court Cards (4 Knights, 4 Queens, 4 Kings) each span 30 degrees of the ecliptic offset by 10 degrees: running from 20° of the preceding sign to 20° of the primary sign (for example, Queen of Wands spans 20° Pisces to 20° Aries).
Which Major Arcana cards correspond to the seven classical planets?
Mercury = I The Magician; Moon = II The High Priestess; Venus = III The Empress; Jupiter = X Wheel of Fortune; Mars = XVI The Tower; Sun = XIX The Sun; and Saturn = XXI The World.
How can I find my personal decan tarot card?
Select your zodiac sign and birth date window in the interactive Zodiac & Decan Matcher above, or enter your full birth date on our Tarot Calculator page.
Methodology & Historical Reference Standards (VIPTarot Cartomancy & Symbolic Systems Research Desk)
RWS-1910— The Pictorial Key to the Tarot (78-Card Archetypal & Symbolic Standard) (A.E. Waite & Pamela Colman Smith, William Rider & Son, London, 1910).GD-BOOK-T-1888— Book T: The Tarot Comprising Manuscripts N, O, P, Q, R (36 Decan Ecliptic Attributions) (Hermetic Order of the Golden Dawn / S.L. MacGregor Mathers, 1888).CASE-BOTA-1947— The Tarot: A Key to the Wisdom of the Ages (22 Hebrew Paths & Cube of Space) (Paul Foster Case, Macoy Publishing Company, 1947).DUMMETT-1980— The Game of Tarot: From Ferrara to Salt Lake City (Historical 78-Card Taxonomy) (Sir Michael Dummett, Duckworth Academic, 1980).W3C-WEBCRYPTO— W3C Web Cryptography API (crypto.getRandomValues Fisher-Yates Permutation Standard) (World Wide Web Consortium (W3C), 2024).
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Tarot Cards by Zodiac Sign
Look up every card associated with Aries through Pisces.
Open Tarot Cards by Zodiac Sign ↗Tarot Birth Card Calculator
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Open Tarot Birth Card Calculator ↗22 Major Arcana Rulers
Review the zodiacal and planetary attributions of all 22 trumps.
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See how Cardinal, Fixed, and Mutable decans structure each suit.
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