How to count outs
After the flop you have seen 5 cards (your 2 and the 3 on the board), so 47 are unseen. After the turn, 46 are unseen. An out is any of those cards that improves you to a hand you expect to win.
- Flush draw (four of one suit): 13 cards of the suit minus the 4 you can see = 9 outs.
- Open-ended straight draw (e.g. 8-7-6-5): four cards at each end = 8 outs.
- Gutshot (inside straight draw, e.g. 9-8-6-5): 4 outs.
- Pocket pair hoping for a set: 2 outs.
- Flush draw plus open-ended straight draw: 9 + 8 minus the 2 cards counted twice = 15 outs.
Do not count an out twice, and discount outs that also help your opponent (a card that completes your straight but pairs the board may give someone a full house).
Exact odds chart
The chance of hitting at least one out, calculated exactly: on the flop, 1 − (non-outs/47 × (non-outs − 1)/46); on the turn, outs/46.
| Draw | Outs | Flop to river | Rule of 4 | Turn to river | Rule of 2 |
|---|---|---|---|---|---|
| Pocket pair to a set | 2 | 8.4% | 8% | 4.3% | 4% |
| Gutshot | 4 | 16.5% | 16% | 8.7% | 8% |
| Two overcards | 6 | 24.1% | 24% | 13.0% | 12% |
| Open-ended straight | 8 | 31.5% | 32% | 17.4% | 16% |
| Flush draw | 9 | 35.0% | 36% | 19.6% | 18% |
| Flush + straight draw | 15 | 54.1% | 60% | 32.6% | 30% |
When the rule of 4 is wrong
- Many outs. Above about 8 outs, ×4 overstates the chance: 15 outs is 54%, not 60%. Use (outs × 4) − (outs − 8) as a closer estimate.
- Only one card is guaranteed. The ×4 figure assumes you see both the turn and the river. If someone can bet again on the turn, you usually only get one card for the price, so use ×2.
- Dirty outs. If some outs also improve your opponent, do not count them.
Turning the percentage into a decision
Odds alone do not say whether to call. Compare them with the pot odds: the share of the final pot that your call makes up. If your chance of hitting is higher than that share, calling is profitable in the long run.
At a home game, the arithmetic is easier when the pot is an exact number in front of everyone. With EasyPoker the pot and every bet show live on each phone, so you only have to count your outs.