Work out tarot card spread odds instantly with clear inputs, formula shown and shareable results.
Cards are dealt without replacement, so the hypergeometric form applies: the chance of none is C(deck - targets, spread) / C(deck, spread). This is straightforward combinatorics, and it shows why a three card spread from a 78 card deck turns up a major arcana card about two thirds of the time.
Chance of none
P(none) = C(deck - targets, spread) / C(deck, spread)
Expected count
expected = spread x targets / deck size
P(none) = C(deck - targets, spread) / C(deck, spread). Cards are dealt without replacement, so the hypergeometric form applies: the chance of none is C(deck - targets, spread) / C(deck, spread).
This is straightforward combinatorics, and it shows why a three card spread from a 78 card deck turns up a major arcana card about two thirds of the time.
Enter cards in the deck, cards in the spread, cards of interest in the deck. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.