Poker Outs Calculator

What an out is

An out is any unseen card that improves your hand to a winner. After the flop there are 47 cards you have not seen, so nine flush outs means nine of those 47 cards complete your flush.

P(hit by river) = 1 − ((47 − outs) / 47) × ((46 − outs) / 46)

How the calculation works

The exact answer comes from the chance of MISSING. With nine outs and 47 unseen cards, you miss the turn 38 times in 47 and then miss the river 37 times in 46; multiply those and subtract from one.

The rule of four and two multiplies your outs instead. It is close for small draws and increasingly optimistic for big ones, because it double-counts the runouts where both cards would have helped.

Outs to equity

4 outs

8.5% to hit on the next card, 16.5% by the river. The rule-of-4 shortcut estimates 16%.

6 outs

12.8% to hit on the next card, 24.1% by the river. The rule-of-4 shortcut estimates 24%.

8 outs

17.0% to hit on the next card, 31.5% by the river. The rule-of-4 shortcut estimates 32%.

9 outs

19.1% to hit on the next card, 35.0% by the river. The rule-of-4 shortcut estimates 36%.

12 outs

25.5% to hit on the next card, 45.0% by the river. The rule-of-4 shortcut estimates 48%.

15 outs

31.9% to hit on the next card, 54.1% by the river. The rule-of-4 shortcut estimates 60%.

Common mistakes

Counting outs that do not win

A card that completes your straight and puts a third flush card out is not an out. Count only the cards that give you the best hand.

Using the rule of four when you cannot see two cards

The rule of four assumes you get both the turn and the river. Facing a bet that will be followed by another one, you are only buying one card — that is the rule of two.

Treating outs as a reason to call on its own

Outs give equity; the pot gives a price. A draw is a call only when the first clears the second.

Practical examples

Flush draw — 9 outs

Nine cards of your suit remain. 19.1% to hit on the next card, 35.0% by the river.

Open-ended straight draw — 8 outs

Either end completes it. 17.0% to hit on the next card, 31.5% by the river.

Gutshot — 4 outs

One rank fills the hole. 8.5% to hit on the next card, 16.5% by the river.

Flush draw plus open-ender — 15 outs

The biggest common draw. 31.9% to hit on the next card, 54.1% by the river.

Key terms

Flush Draw

Nine outs to complete a flush — ~35% equity with two cards to come.

Gutshot Straight Draw

Four outs to complete an inside straight — ~16% equity with two cards to come.

Open-Ended Straight Draw

Eight outs to complete a straight — ~31% equity with two cards to come.

Key takeaway

The rule of four is a shortcut, not the answer. It drifts upward as the out count rises, so with big draws use the exact figure before committing a stack.