Counting Outs in Poker + the Rule of 2 and 4
How to count your outs on the flop and turn, then turn them into a percentage instantly with the rule of 2 and 4 – with worked draw examples.
7 min read · Updated July 6, 2026
When you have a drawing hand – a flush or straight that is not complete yet – the key question is: how likely am I to make it? The answer starts with counting your outs, the cards still to come that would give you the winning hand. Once you can count outs, the rule of 2 and 4 converts them into a percentage in your head. Together they are the arithmetic behind every good call on a draw.
What is an out?
An out is any unseen card that improves your hand to one that will probably win. There are 52 cards in the deck; you subtract the ones you can see (your two hole cards and the community cards on the board) and count how many of the remaining cards help you. The cleanest example is a flush draw.
A suit has 13 cards. You can see four hearts (two in your hand, two on the board), so nine hearts remain unseen. That is nine outs to complete your flush.
Common draws and their outs
| Draw | Outs |
|---|---|
| Flush draw (four to a flush) | 9 |
| Open-ended straight draw | 8 |
| Gutshot (inside) straight draw | 4 |
| Two overcards to the board | 6 |
| Flush draw + open-ended straight draw | 15 |
An open-ended straight draw – four cards in a row, like 9♣8♥ on a 7♠6♦ board – can be completed from either end (a ten or a five), and there are four of each, for eight outs. A gutshot needs one specific rank in the middle, so only four outs.
The rule of 2 and 4
Counting outs tells you how many cards help; the rule of 2 and 4 turns that into a probability without any hard math:
- One card to come (for example, turn to river): multiply your outs by 2.
- Two cards to come (flop to river, when you expect to see both): multiply your outs by 4.
So a nine-out flush draw is roughly 9 × 4 = 36% to hit by the river from the flop, and about 9 × 2 = 18% to hit on the turn alone. The true figures are 35% and 19.6% – close enough to make the decision, and you can do it instantly.
A worked example
You hold A♥K♥ on a flop of Q♥7♥2♣. You have the nut flush draw: nine outs. Using the rule of 4, you are about 36% to make your flush by the river. That single number is what you carry into the next decision – comparing it to the price of a call, which is the domain of pot odds.
Make the count automatic
Counting outs under pressure is a skill you build by reps, not by reading. Poker School’s outs trainer deals you live boards and asks you to click every out against the clock, checking your count with the same engine that runs the tables. It is free – create an account to start drilling, then learn how to price your calls in the pot odds guide.
Frequently asked questions
- What are outs in poker?
- Outs are the unseen cards that would improve your hand to one that is likely to win. For example, a flush draw with four cards of a suit has nine outs – the nine remaining cards of that suit.
- What is the rule of 2 and 4?
- A shortcut for turning outs into a percentage. Multiply your outs by 2 for the chance of hitting on the next single card, or by 4 for the chance of hitting across both the turn and river combined.
- How many outs does a flush draw have?
- Nine. A suit has 13 cards; if you can see four of them (two in your hand, two on the board), nine remain unseen – so a flush draw has nine outs.
- How many outs does an open-ended straight draw have?
- Eight – the four cards at each end of the four-card sequence complete the straight. A gutshot (inside) straight draw has only four outs.
Put it into practice
Reading is the start. Poker School turns every concept above into interactive lessons, graded table scenarios, and real-stakes practice against personality bots – free to start.