How to Calculate Pot Odds: The One Step Before You Call
Before you call, work out one number: the call amount divided by the total pot after you call. That is the equity you need. Compare it with your hand's equity and you no longer have to decide on feel.
Translated from the Traditional Chinese original and checked by AI.
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Friday home game. You are in the big blind with , and the flop comes . You have a flush draw. The pot is 100 and the button (BTN) bets 50. A voice in your head says, "One card away from a flush, just call."
But is the call actually worth it? What if the bet were 100, or 150? Would you still call? If you go by feel, the answer changes every time. This lesson teaches you to work out one number before you call. Once you have it, the answer gets much clearer.
The three numbers to find before you call
Every time you face a bet, find these three numbers first:
The pot before the bet: 100 in our example.
Your opponent's bet: 50.
The amount you have to call: 50.
Add all three and you get the total pot after you call: 100 + 50 + 50 = 200. You pay 50 to compete for those 200.
Pot odds: ratio and percentage
Pot odds compare what you have to pay with what you can win.
As a ratio: before you call, the pot holds 150 (100 + your opponent's 50), and you pay 50, so it is 150 : 50 = 3:1.
As a percentage: 50 ÷ 200 = 25%. That means you need at least a 25% chance of winning this pot for the call to break even in the long run.
The two are the same thing (3:1 means you put in 1 share out of 4, which is 25%). I suggest you get used to percentages, because hand equity is already expressed as a percentage. "I need 25% and I have 19%" tells you at a glance whether it is enough, with no conversion.
The formula is one line:
Equity needed = call amount ÷ (total pot after you call)
Worked examples: three bet sizes
Same pot of 100:
Opponent bets 50 (half pot): you call 50, total pot 200, 50 ÷ 200 = 25%.
Opponent bets 100 (full pot): you call 100, total pot 300, 100 ÷ 300 ≈ 33%.
Opponent bets about 1/3 pot: the equity you need is 20% (the table below uses whole numbers to show it).
The tool below is already filled in for the first case. pot is the pot before your call, which is the 100 plus your opponent's 50:
The tool shows 25%. Now change pot to 200 and call to 100 (a pot-sized bet) and watch the equity you need become 33%.
Quick quiz
The pot is 60 and your opponent bets 30 (half pot). What is the minimum equity you need to call?
Pick one answer.
Cheat sheet: common bet sizes
As long as the bet is the same fraction of the pot, the equity you need is the same, whatever the pot size. To get whole numbers, this table uses a pot of 120:
| Bet size | Opponent's bet | Your call | Total pot | Equity needed | Ratio |
|---|---|---|---|---|---|
| 1/3 pot | 40 | 40 | 200 | 20% | 4:1 |
| 1/2 pot | 60 | 60 | 240 | 25% | 3:1 |
| 2/3 pot | 80 | 80 | 280 | about 28.6% | 2.5:1 |
| Full pot | 120 | 120 | 360 | about 33.3% | 2:1 |
(Percentages in the table are rounded to one decimal place; in the text I sometimes say 33% for short.) Memorize these four rows and you will rarely need to calculate at the table. The bigger the bet, the more equity you need, but even against a pot-sized bet you only need one third.
Quick quiz
The pot is 40 and your opponent bets 40 (full pot). What is the minimum equity you need to call?
Pick one answer.
Putting a hand on it: is the flush draw good enough?
Back to the hand at the top. There are 13 hearts in the deck, and you can see 4 of them (2 in your hand, 2 on the board), so 9 cards will complete your flush. Those 9 cards are your outs. The number of cards you have not seen on the flop is 52 − 5 = 47.
Next card only (the turn): 9 ÷ 47 ≈ 19.1%.
Seeing both the turn and the river: about 35% (1 − (38/47 × 37/46) ≈ 35.0%).
Your opponent bet half pot, so you need 25%. Which number should you compare it with?
If both of you still have chips behind, your opponent will probably bet again on the turn. The 50 you call now buys you one card, so the honest number is 19.1%. 19.1% is less than 25%, so looking only at the pot odds right now, this call is not enough.
That does not mean the answer is to fold. Pot odds only count the money in the pot today. They ignore the extra money you can win when you hit your flush. How this hand ends up depends on the next section, on implied odds.
The 35% figure only counts when you are guaranteed to see both cards without paying again. The classic case is when your opponent is already all-in and no more betting is possible.
When this rule breaks down
Pot odds only count "the money on the table right now." In real games, a few other things matter:
Implied odds: if you can win more from your opponent after you hit, a call that looks short on pot odds can still be profitable. Take the opening hand. You call 50. On the turn you hit your flush 9/47 of the time and win the current 150 plus some extra amount X from your opponent. The other 38/47 of the time you miss and lose the 50. To break even you need 9 × (150 + X) ≥ 38 × 50, which is 1350 + 9X ≥ 1900, so X ≥ about 61. In other words, after you hit the flush, you need to win about 61 more on average, roughly 60% of the flop pot of 100. With deep stacks (say both players have around 100bb) and an opponent who pays off when he connects, this is usually achievable, so the call is generally reasonable. Two things make it less easy: you are in the big blind, out of position, so it is harder to extract money after the turn; and your jack-high flush is not the nuts, so if your opponent holds a flush with or , you lose even more when you hit. (This is a simplification: it ignores the chance to hit on the river after missing the turn.)
Reverse implied odds: you can hit and still lose, and lose more. For example, you make a small flush and your opponent has a bigger one, or you make top pair with a weaker kicker. Discount the equity of these hands.
All-in versus facing further bets: when your opponent is all-in, calling lets you see every card, so the two-card equity is the fair comparison. When more betting is coming, use the one-card equity.
Multiway pots: when several players call, the pot gets bigger and the odds look better. But the more opponents there are, the more likely one of them beats you. And if players behind you have not acted yet, they may raise, which makes your call a wasted payment.
These points only make your judgment more refined. The starting point is the same step: work out how much equity you need.
Key takeaways
Equity needed = call amount ÷ total pot after your call. Remember to include your own call.
Percentages are easier than ratios because you can compare them directly with your hand's equity.
Common sizes: 1/3 pot 20%, 1/2 pot 25%, 2/3 pot about 28.6%, full pot about 33.3%.
When you will still face bets after the flop, use the one-card equity for a draw (about 19.1% for a flush draw), not 35%.
When one-card equity is not enough, work out how much more you must win when you hit. This flush draw facing a half-pot bet needs about 61 more when you hit, which is usually worth a call when stacks are deep.
Pot odds are a starting point, not the whole picture. Doing the math right does not mean you win every hand, and short-term swings are normal.
Next step
Use this drill to make the common sizes a reflex, so you can name the equity needed without thinking:
To enter your own numbers, open the pot odds calculator. The next lesson, Outs and the rule of 2 and 4, shows you how to estimate hand equity quickly at the table, so you have a number to compare with the one you worked out in this lesson.