Poker outs calculator.

Answer

With 9 outs (such as a flush draw) the exact chance to hit on the turn is 19.15%, by the river from the flop is 34.97%, and on the river from the turn is 19.57%. The rule of 4 gives 36% and the rule of 2 gives 18%.

Worked example

On the flop you hold a flush draw with 9 outs. Unseen cards: 52 - 2 in your hand - 3 on the board = 47. Both remaining cards miss with probability (38 / 47) x (37 / 46) = 65.03%, so you hit by the river with 34.97%. If the turn misses, 46 cards are unseen and the river chance is 9 / 46 = 19.57%. Facing a bet of 10 into a pot of 40, the pot after the bet is 50 and you pay 10 to call: required equity 10 / (50 + 10) = 16.67%.

How it works

Unseen cards. In Texas hold'em you hold two cards and the board shows three after the flop, one more on the turn, and one on the river. After the flop there are 47 unseen cards; after the turn there are 46.

Exact odds. One card to come: outs / unseen. Two cards to come from the flop: 1 - C(unseen - outs, 2) / C(unseen, 2), the chance that not both cards miss.

Rule of 2 and 4. A common rule of thumb, not a published standard, multiplies your outs by 2 for one card to come or by 4 for two cards to come to estimate the percentage. It is close for modest out counts and overstates large ones. The Pot odds article on Wikipedia gives a worked example in which 9 outs on the turn are 9/46 (19.6%) exactly while the rule of 2 and 4 estimates 18%.

Pot odds. Pot odds are the ratio of the current pot to the cost of a call. With the pot before the bet P and a bet B, the pot you can win is P + B for a cost of B, so the break-even equity is B / (P + 2B). If your chance to hit is higher than that, the call has positive expected value on pot odds alone. The result ignores implied odds, shared outs and whether your outs are clean.

Sources and basis (opened 2026-10-08): Texas hold 'em (Wikipedia) for the hole cards, flop, turn and river; Pot odds (Wikipedia) for pot odds and the rule of 2 and 4.

FAQ

What are outs in poker?

Outs are the unseen cards that would improve your hand to one you expect to win. A flush draw with four of one suit on the flop has 9 outs because 13 - 4 = 9 cards of that suit remain.

How do I calculate the chance of hitting my outs?

With one card to come, divide outs by the unseen cards (47 on the flop, 46 on the turn). With two cards to come, subtract from 1 the chance that both cards miss.

What is the rule of 2 and 4?

A rough way to estimate equity: multiply outs by 4 on the flop with two cards to come, or by 2 with one card to come. It is a rule of thumb, not a published standard, and it drifts for large numbers of outs.

How much equity do I need to call?

Bet divided by the pot after the bet plus your call. For a bet of 10 into a pot of 40 you need 16.67%.

Does this account for implied odds?

No. It uses only the chance to hit and the current pot. Money you might win on later streets and outs that also help your opponent are not counted.