--- title: "18 Outs on the Turn: Odds to Hit" url: "https://georgelipoker.com/outs/18-outs-turn.md" canonical_url: "https://georgelipoker.com/outs/18-outs-turn" last_updated: "2026-10-23" type: "reference" summary: "18 outs on the turn: a 39.13% chance on the river, 1.56 : 1 against. See the rule of 2 error and the bets you can call." related: ["https://georgelipoker.com/outs.md"] --- # 18 Outs on the Turn: Odds to Hit 18 outs on the turn: a 39.13% chance on the river, 1.56 : 1 against. See the rule of 2 error and the bets you can call. With 18 outs on the turn, you complete your hand on the river 39.13% of the time. The page below gives the odds against, the error of the rule of thumb and the bets that chance can pay for. - Chance to hit on the river: 39.13% (18 outs, one card to come) - Odds against: 1.56 : 1 - Rule of 2 estimate: 36% (-3.13 points from the exact chance) - Unseen cards: 46 ## The count behind 18 outs on the turn With 39.13% on the river, the draw fails 60.87% of the time and lands the rest. That is enough to call a bet of up to 180.00% of the pot. - Unseen cards: 46 - Your outs: 18 - Cards that miss: 28 - Chance on the river: 39.13% - Chance on the next card (the river): 39.13% - Odds against hitting: 1.56 : 1 - Estimate from the rule of 2: 36% - Error of the rule of 2: -3.13 points - Chance on the river = k / u, with u = 46 unseen cards - For 18 outs: 18 / 46 = 39.13% One card is left to come out of 46 unseen. 18 of them are outs and 28 miss, so the chance is 18 divided by 46, which is 39.13%. 36% from the quick rule sits 3.13 points under the true 39.13%, so the shortcut is pessimistic here. The adjusted rule only applies from the flop above 8 outs, so 18 outs on the turn use the plain rule of 2: 2 x 18 = 36%. ## Which holding has 18 outs? A count of 18 is a combination, not a textbook draw. Add up the helpful cards from each part of your hand and take away any that repeat. Suppose up to 3 of your outs also help a stronger hand. The effective count drops to 15, and the chance on the river drops to 32.61%. 18 outs on the turn when some outs are shared with a better hand | Shared outs | Effective outs | Chance on the river | Chance given up | | --- | --- | --- | --- | | 0 | 18 | 39.13% | 0.00 points | | 1 | 17 | 36.96% | 2.17 points | | 2 | 16 | 34.78% | 4.35 points | | 3 | 15 | 32.61% | 6.52 points | ## The bets 18 outs can call on the turn Draw the line at 39.13%: any bet that needs less equity than that is a call. Here that covers 9 of the 12 bet sizes. 18 outs on the turn against every bet size, with your chance on the river at 39.13% | Bet size | Equity a call needs | Margin over it | Verdict | | --- | --- | --- | --- | | 1/4 pot | 16.67% | +22.46 points | Call | | [1/3 pot](https://georgelipoker.com/call-or-fold/18-outs-turn-vs-third-pot.md) | 20.00% | +19.13 points | Call | | 2/5 pot | 22.22% | +16.91 points | Call | | 1/2 pot | 25.00% | +14.13 points | Call | | 2/3 pot | 28.57% | +10.56 points | Call | | 3/4 pot | 30.00% | +9.13 points | Call | | full pot | 33.33% | +5.80 points | Call | | 1.25x pot | 35.71% | +3.42 points | Call | | 1.5x pot | 37.50% | +1.63 points | Call | | 2x pot | 40.00% | -0.87 points | Fold | | 3x pot | 42.86% | -3.73 points | Fold | | 4x pot | 44.44% | -5.31 points | Fold | Your 39.13% stretches to a bet of 180.00% of the pot. Put in dollars, that is $180 when the pot holds $100. ## Nearby counts on both streets If your count is off by one, the chance moves by about 2.17 points. These rows show the counts near 18 on the flop and the turn. Counts near 18: the chance by the river on the turn and on the flop | Outs | Turn, by the river | Flop, by the river | | --- | --- | --- | | [16](https://georgelipoker.com/outs/16-outs-turn.md) | 34.78% | 56.98% | | [17](https://georgelipoker.com/outs/17-outs-turn.md) | 36.96% | 59.76% | | 18 (this page) | 39.13% | 62.44% | | [19](https://georgelipoker.com/outs/19-outs-turn.md) | 41.30% | 65.03% | | [20](https://georgelipoker.com/outs/20-outs-turn.md) | 43.48% | 67.53% | - [18 outs on the flop](https://georgelipoker.com/outs/18-outs-flop.md): 62.44% by the river. - [17 outs on the turn](https://georgelipoker.com/outs/17-outs-turn.md): 36.96% on the river. - [19 outs on the turn](https://georgelipoker.com/outs/19-outs-turn.md): 41.30% on the river. ## The river is the last card You do not need a second view on the turn. The 39.13% chance is final, and against a half-pot price of 25.00% it leaves +14.13 points: Call. ## Questions ### How good is a draw with 18 outs on the turn? With 18 outs on the turn you hit on the river 39.13% of the time, about 39 of every 100 hands, because 18 of the 46 unseen cards are outs. The odds against are 1.56 : 1. ### Is the rule of 2 close enough for 18 outs? The rule of 2 gives 36% for 18 outs against an exact 39.13%, an error of -3.13 points. The shortcut sits below the true chance, so the exact figure is better for you. ### Do 18 outs on the turn justify a call, and against which bets? At 39.13% on the river, you can call 9 of the 12 bet sizes. A half-pot bet needs 25.00%, a margin of +14.13 points, so against half the pot the verdict is Call. The largest bet you can call is 180.00% of the pot, or $180 on a $100 pot. ### How do I adjust a count of 18 for outs that help an opponent? Take them off the count first. With one shared out the chance on the river falls from 39.13% to 36.96%, and with 3 shared it falls to 32.61%, a loss of 6.52 points. The effective count is then 15 outs. ## How this is computed The chance to hit on the river from the turn is k / 46, where 46 is the number of unseen cards and k is your effective outs. For 18 outs that is 18 / 46 = 39.13%. The next card is the river, so both chances are the same. The rule of 2 figure is 2 x k, here 36%, and its error is that figure minus the exact chance in percentage points, here -3.13 points. The chance counts only the 46 cards you cannot see, each equally likely. It ignores what an opponent may hold and any money still to be won. Verdicts compare your chance with the bet over the pot plus two bets, on a $100 pot. Computed from the closed form by the GeorgeLiPoker math library. ## Related pages - [Outs calculator](https://georgelipoker.com/tools/outs-calculator.md): Enter your own count and street. - [Pot odds calculator](https://georgelipoker.com/tools/pot-odds-calculator.md): Enter a pot and a bet to see the equity a call needs. - [Outs and odds to hit](https://georgelipoker.com/outs.md): The chance to hit for every count on both streets. - [18 outs on the flop](https://georgelipoker.com/outs/18-outs-flop.md): The same count with two cards to come. - [Pot odds for a pot-size bet](https://georgelipoker.com/pot-odds/pot-size.md): The equity a pot-size call needs. - [Pot odds for a 4x-pot bet](https://georgelipoker.com/pot-odds/4x-pot.md): The equity a 4x-pot call needs. - [Hand equity](https://georgelipoker.com/equity.md): Your chance to win against a named hand. ## Related - [Outs and Odds to Hit by Street](https://georgelipoker.com/outs.md)