Step 1: count your outs
An out is any card that turns your hand into a likely winner. You hold on a board of . Thirteen hearts exist, four are visible, so nine remain. You have nine outs to a flush.
| Draw | Outs | Flop to river | Turn to river |
|---|---|---|---|
| Gutshot straight | 4 | 16.5% | 8.7% |
| Two overcards | 6 | 24.1% | 13.0% |
| Open-ended straight | 8 | 31.5% | 17.4% |
| Flush draw | 9 | 35.0% | 19.6% |
| Flush + gutshot | 12 | 45.0% | 26.1% |
| Flush + open-ended | 15 | 54.1% | 32.6% |
Discount outs that also help your opponent. If the board pairs while you chase a flush, your flush may lose to a full house.
Step 2: the rule of 2 and 4
On the flop with two cards to come, multiply outs by four. On the turn with one card to come, multiply by two. The estimate runs a little high above about eight outs, so with big draws subtract a few points. It is accurate enough to make decisions at the table in seconds.
Step 3: pot odds
Pot odds compare the cost of a call with what you can win. The fastest way to use them is as a percentage:
Equity needed = amount to call ÷ (pot after you call)
The pot is $100. Your opponent bets $50. You must call $50 to win a pot that will total $200. You need 50 ÷ 200 = 25% equity.
| Opponent's bet | Equity you need to call |
|---|---|
| ¼ pot | 16.7% |
| ⅓ pot | 20% |
| ½ pot | 25% |
| ⅔ pot | 28.6% |
| ¾ pot | 30% |
| Pot | 33.3% |
| 2× pot | 40% |
Compare the two numbers. With a flush draw on the turn (about 20%) facing a pot-sized bet (33% needed), calling loses money unless you expect to win more later.
Step 4: implied and reverse implied odds
Implied odds are the chips you will win on later streets when you hit. A small pair calling a raise hoping to flop a set wins only about 12% of the time, but when it hits it often wins an entire stack. Reverse implied odds are the opposite: hands like a weak top pair that win small pots when ahead and lose big ones when behind.
Equity is about ranges, not hands
You will rarely know your opponent's exact cards. Strong players estimate equity against a range: "this player raises the river with sets, two pair and the occasional missed draw." Your call is profitable if your equity against that whole range beats the price. Run the numbers yourself in our pot odds calculator.
Frequently asked questions
What is the rule of 2 and 4?
Multiply your outs by 4 on the flop (two cards to come) or by 2 on the turn (one card to come) to estimate your percentage chance of hitting. Nine flush outs on the flop is about 36%; the exact figure is 35%.
How do you calculate pot odds?
Divide the amount you must call by the total pot after your call. Calling $50 into a pot that will be $200 needs 25% equity.
What are implied odds?
The extra money you expect to win on future streets when you hit. They justify calling with draws that the current price does not.