One can calculate the probability of drawing at least ONE of a set of target
cards from a deck by using the following formula, in which D=deck size,
T=number of target cards and H=number of cards to be drawn into the hand:
The form below allows you to submit numbers to the card calculator program. The numbers will be crunched on another machine, and you will be told the probability of drawing one or more specific target cards from a random deck of any size with any number of draws.
When you tell the program how many cards are in the deck, count all unidentified cards in people's hands, and discount all cards that you know the identity of.
Likewise, when you tell the program how many target cards are in the deck, discount all target cards that you know the identity of.
EX: Henry and John are playing cards. They each have a hand of four cards, from a normal 52 card deck. John has an ace, a ten, and 2 fours. John doesn't know what Henry has. If John draws three more cards, and he wants to draw at least one more ace, to calculate his chances with this program he would answer:
48 cards in the deck (52 card deck, minus the cards in John's hand).
3 target cards (4 aces in the deck, minus the one John knows about).
3 cards to be drawn.
You must make at least one draw, and have at least one target card. The deck must have at least as many cards as will be drawn. The deck must have at least as many cards as there are target cards.
All numbers must be input as positive integers. Neither the size of the hand, nor the number of target cards, can exceed the size of the deck.
Click here for copy of this program.