What is a pot odds and outs calculator?
A pot odds calculator tells you how often your hand must win for a call to break even, and compares that with how often it will win. With a pot of 100 units, a bet of 50 into it, nine outs and two cards to come, you need 25.0% equity to call and you have about 35.0%. The call is profitable on those numbers, with an expected value of about +19.9 units.
Pot odds are a price: what you must pay to call compared with what you can win. Outs are the unseen cards that complete your hand. The calculator turns both into percentages and compares them. It uses exact card counting, not a rule of thumb, and then shows how close the common “rule of 2 and 4” gets. It does not know what your opponent holds, so it cannot tell you whether your outs are clean.
How do you use the pot odds and outs calculator?
- Enter the pot. This is the size of the pot before the bet you are facing.
- Enter the bet you face. This is the amount you must call.
- Enter your outs. Count the unseen cards that make your hand best. Be strict: do not count cards that also help your opponent.
- Choose the cards to come. Use 2 on the flop (turn and river) and 1 on the turn.
- Enter the unseen cards. In hold’em this is 47 on the flop and 46 on the turn, counting your two hole cards and the board as seen.
- Compare the two percentages. If your equity is above the equity needed, the call has a positive expected value on these numbers.
Example: Pot 100, bet 50, 9 outs, 2 cards to come, 47 unseen. Equity needed = 50 / (100 + 50 + 50) = 25.0%. Your equity = 1 – C(38,2) / C(47,2) = 1 – 703 / 1,081 = 34.97%. The rule of 4 would say 36%.
How are pot odds and equity calculated?
The price of a call: you pay the call to win the pot plus the bet. So the equity you need is call / (pot + bet + call). If you have the exact number of outs, the chance of hitting at least one of them in k cards from U unseen cards is 1 – C(U – outs, k) / C(U, k), where C(n, k) is the number of ways to choose k cards from n. The expected value of the call is equity x (pot + bet) – (1 – equity) x call.
| Step | Working | Result |
|---|---|---|
| Equity needed | 50 / (100 + 50 + 50) | 25.00% |
| Cards that miss (both) | C(38, 2) | 703 |
| All two-card draws | C(47, 2) | 1,081 |
| Equity with 9 outs | 1 – 703 / 1,081 | 34.97% |
| EV of the call | 0.3497 x 150 – 0.6503 x 50 | +19.94 |
The needed equity depends only on the size of the bet compared with the pot. The table shows what you need against common bet sizes into a pot of 100.
| Bet size | Bet in units | Equity needed to call |
|---|---|---|
| Quarter pot | 25 | 16.7% |
| Half pot | 50 | 25.0% |
| Two thirds pot | 67 | 28.6% |
| Full pot | 100 | 33.3% |
| Twice the pot | 200 | 40.0% |
How accurate is the rule of 2 and 4?
Players often multiply outs by 4 on the flop and by 2 on the turn to estimate equity. The table compares that shortcut with the exact figure for a hold’em hand with 47 unseen cards on the flop and 46 on the turn. The shortcut is close for small draws and overshoots for big ones. With 15 outs on the flop it says 60% while the exact figure is 54.1%.
| Outs | Flop exact (2 cards) | Flop rule of 4 | Turn exact (1 card) | Turn rule of 2 |
|---|---|---|---|---|
| 4 | 16.5% | 16% | 8.7% | 8% |
| 6 | 24.1% | 24% | 13.0% | 12% |
| 8 | 31.5% | 32% | 17.4% | 16% |
| 9 | 35.0% | 36% | 19.6% | 18% |
| 12 | 45.0% | 48% | 26.1% | 24% |
| 15 | 54.1% | 60% | 32.6% | 30% |
A common adjustment is to subtract one point for each out above 8 from the rule of 4 figure, which brings the flop shortcut much closer. The calculator removes the need for the shortcut, but the table is useful at the table when you have no calculator.
When does a close call become a clear call or fold?
The default hand is a clear call: you need 25.0% and have 35.0%. With 8 outs your equity drops to 31.5%, which still covers the 25.0% needed. Make the bet bigger, to 100 into 100, and you need 33.3%, so nine outs (35.0%) are barely enough and eight outs (31.5%) fall short. Try these in the calculator to see how quickly the answer flips.
Remember that the numbers are about one decision. If you are on the flop and expect to face another bet on the turn, the price of seeing the river is higher than the first call alone suggests.
What does the calculator leave out?
- Your opponent’s hand. Some outs may be dead if they hold a better draw or a made hand that improves too.
- Implied odds. Bets you might win later when you hit are not counted.
- Reverse implied odds. Money you might lose when you hit and are still second best is not counted.
- Folding equity. The chance your opponent folds to a raise is not modelled.
- Tournament effects. The value of chips changes near the money or the final table.
- Rake. Fees taken from the pot reduce what you win.
What mistakes do people make with pot odds?
- Counting too many outs. Cards that also complete a better hand for your opponent are not clean outs.
- Forgetting the call is part of the pot. You win the pot plus the bet, but you also put in the call, hence the 200 in the denominator above.
- Using the rule of 4 on the turn. With one card to come, use the rule of 2.
- Treating positive EV as a promise. A call with 35% equity still loses about 65 times in 100.
- Ignoring the stack. If calling uses most of your stack, variance matters more than the average.
What should you try next?
Change the cards to come from 2 to 1 and watch the equity fall. Then try raising the bet to the size of the pot. For a general view of whether a bet is worth its price, use the expected value calculator. To see what a long run of calls does to a bankroll, use the risk of ruin calculator. If you play for money, the Safer play toolkit has tools to set limits first.
How to read the result
The large number is the equity you need to call: the share of the time your hand must win for the call to break even. The panel shows your exact equity from the outs you entered, the rule of 2 and 4 estimate for comparison, and the expected value of the call in units. If your equity is above the equity needed, the call is profitable on these numbers. The calculation counts cards only and does not know what your opponent holds.
How it is calculated
Equity needed = call / (pot + bet + call). Your equity with k cards to come, U unseen cards and O outs = 1 - C(U - O, k) / C(U, k). The rule of thumb is outs x 4 with two cards to come and outs x 2 with one. The expected value of the call = equity x (pot + bet) - (1 - equity) x call.
Worked example
Worked example
Pot 100, bet 50, 9 outs, 2 cards to come, 47 unseen. Equity needed = 50 / 200 = 25.0%. Your equity = 1 - C(38,2) / C(47,2) = 1 - 703 / 1,081 = 34.97%. Rule of 4: 36%. EV of the call = 0.3497 x 150 - 0.6503 x 50 = +19.94 units. With 8 outs the equity is 31.45%.
Limits
The calculator counts cards only. It cannot tell if your outs are clean, and it ignores your opponent's hand, implied and reverse implied odds, folding equity, rake and tournament effects. It treats one decision and does not look at later bets. It assumes your outs are drawn from the unseen cards at random. A call with positive expected value still loses most of the time when the equity is under 50%. Results are estimates, not predictions.