A flush draw is four cards of the same suit after the flop, needing one more to complete. It is the most common strong draw in Hold'em, and knowing its exact odds turns a guess into a simple comparison with the price you are being offered.
Flush draw odds at a glance
| Draw | Outs | Flop to turn | Turn to river | Flop to river |
|---|---|---|---|---|
| Flush draw | 9 | 19.1% | 19.6% | 35.0% |
With nine outs you hit on the turn 19.1% of the time, about 4.2 to 1 against. If you see both the turn and the river, for example because you are all-in on the flop, you complete the flush 35.0% of the time, or 1.9 to 1 against.
Where the numbers come from
After the flop you know five cards: your two and the three on the board. That leaves 47 unseen cards. Thirteen cards make up a suit and you can see four of them, so 9 cards complete your flush. The chance of hitting on the turn is 9 ÷ 47. To hit by the river, take the chance of missing twice, 38/47 × 37/46, away from 100%.
The quick shortcut is the rule of 2 and 4: multiply outs by 2 for one card and by 4 for two cards. For a flush draw that gives 18% and 36%, very close to the exact figures.
When should you call with a flush draw?
Compare your chance of hitting with the share of the final pot you have to put in. Facing a half-pot bet you need 25% equity; facing a pot-sized bet you need 33.3%. With one card to come, a flush draw has 19.1%, so on pure pot odds it is not quite enough to call even a half-pot bet.
What makes most flush draw calls correct is implied odds: the money you expect to win on later streets when you hit. In a $100 pot facing a $50 bet, you need to win about $61 more on average after hitting to break even on the call. Against opponents who pay off big bets, that is often realistic; against tight players who fold when the third suited card lands, it may not be.
When a flush draw is weaker than it looks
- Low flush draws. If you hold the six and seven of hearts, a bigger flush can beat you. Count your outs lower when the board makes that likely.
- Paired boards. On a paired flop, some of your flush cards can give an opponent a full house.
- Three-flush boards. If the flop already has three cards of your suit and you hold one, you need two more running cards, a much weaker draw.
Semi-bluffing a flush draw
Because a flush draw has decent equity even when called, it is one of the best hands to bet or raise with. You can win the pot right away when your opponent folds, and still hit 35.0% of the time if they call all the way. The EV calculator shows how much fold equity you need for a semi-bluff to pay.
Check any draw with the poker outs chart or the pot odds calculator, and see how often your suited hands flop a draw on the starting hand pages.