The arithmetic
To call a bet of B into a pot of P, you risk B to win P + B. So you need to win at least B / (P + 2B) of the time.
That is the whole calculation. Everything else in this section is applying it.
Every common bet size
| Bet as a share of the pot | You are getting | Equity needed | Flush draw calls? |
|---|---|---|---|
| Quarter pot | 5.00 to 1 | 16.7% | Yes |
| Third pot | 4.00 to 1 | 20.0% | Yes |
| Half pot | 3.00 to 1 | 25.0% | Yes |
| Two thirds | 2.50 to 1 | 28.6% | Yes |
| Three quarters | 2.33 to 1 | 30.0% | Yes |
| Full pot | 2.00 to 1 | 33.3% | Yes |
| Twice the pot | 1.50 to 1 | 40.0% | no |
Read the last column. A flush draw at 34.97% profitably calls any bet up to the size of the pot. A gutshot at 16.47% needs a bet of about a fifth of the pot or less, which almost nobody makes.
The mistake in using the two-card number
The 34.97% figure for a flush draw covers the turn and the river. It is the right number only if you are all in, or certain to see both cards for free.
Facing a bet on the flop with more betting to come, the honest number is the one-card equity: 19.57%. Using the two-card figure to justify a flop call, then folding to a turn bet, is the single most common way players talk themselves into a losing call.
Implied odds, briefly
Pot odds count the money already there. Implied odds count what you expect to win later if you hit.
They are real and they are routinely overestimated. A gutshot needing 33.3% but getting 16.5% is only a call if you will genuinely extract several times the current bet when it lands, from an opponent with a hand strong enough to pay. Both of those conditions fail more often than players assume.
Our outs and equity page has the exact figure for every common draw.
Frequently Asked Questions
- How much equity do I need to call a pot-sized bet?
- 33.3%. You are risking one unit to win three, counting your own call.
- Can I call a pot-sized bet with a flush draw?
- Just about: 34.97% against 33.3% needed, if you are seeing both cards. Facing further betting, use the one-card figure of 19.57%.
- What is the formula for pot odds?
- Equity needed = B / (P + 2B), where B is the bet and P is the pot before it.
- Should I use the two-card or one-card equity?
- One card, unless you are all in or certain to see the river for free. The two-card figure assumes betting stops, which it usually does not.
Equities on this page are computed by enumerating every one of the 1,712,304 boards that can follow the two hands shown, not by simulation, so they are exact for those specific cards. Draw and flop probabilities are exact combinatorics. The hand evaluator is checked against known orderings and the equities against published ranges before publication. Note that published figures usually quote one number per hand class while the real value moves with the suits, which is why this section names the exact cards.