Block 05 · Poker Math: Pot Odds, Equity & Outs

Counting outs: how many for a flush or straight draw

Lesson 1 of 12 ~2 min read 20-question test

Counting outs is where poker math starts: outs are the unseen cards that rescue your hand, and once you know what outs are in Texas Hold'em, every draw becomes a problem you can solve at the table with quick pot odds.

An out is a card that saves you

An out is any unseen card that turns your losing hand into a likely winner. Before you can price a draw, you have to count them accurately, and count only the ones that actually help.

Flush draw: you hold As Ks, the flop is Qs 7s 2h. Four spades are visible, so nine spades remain — 9 outs.

The five draws worth memorizing

Most spots reduce to a handful of shapes. Flush draw = 9 outs. Open-ended straight draw = 8. Gutshot = 4. Two overcards = 6. A pocket pair hoping to hit a set = 2. Learn these and you can eyeball almost any hand.

Open-ended straight draw: 9h 8h on 7c 6d 2s. Any 10 or any 5 makes the straight — 4 + 4 = 8 outs.
Gutshot: Jd 10d on 8c 7s 2h. Only a 9 fills J-10-9-8-7 — just 4 outs, half of an open-ender.

Overcards and set-mining

When you miss the flop with two high cards, each overcard can pair for 3 outs, giving 6 in total. And a pocket pair that flops no set has just 2 outs to make trips — the reason you need cheap, deep-stacked spots to set-mine.

Two overcards: Ac Kd on 9s 6h 2c. Three aces plus three kings pair you up — 6 outs.
Interactive · Calculator

Pot odds & outs calculator

The single most useful piece of poker maths. Set the pot, what you must call, and how many outs you hold — and see instantly whether the call is +EV.

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Your equity
Equity needed to call
Pot odds
Rule of 4 / 2
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Two cards to come assumes the money is all-in now. Facing a bet on a single street, use one card — you'll have to pay again to see the river.

Discount your tainted outs

Not every out is clean. A card that completes your straight might also complete an opponent's flush, or pair the board and fill a full house. When an out could hand someone a better hand, shave it from your count — better to slightly under-count than to draw dead to a card you thought was gold.

Tainted: 10c 9c on 8h 7h 2h. A 6 or J makes your straight, but the board is already all hearts — a 6h or Jh puts a fourth heart out and could complete a rival flush, so discount those two outs.
Before the test — remember
  • Memorize the core counts: flush 9, open-ended straight 8, gutshot 4, two overcards 6, pair-to-set 2.
  • Use the Rule of 4 and 2 — outs times 4 on the flop, times 2 on the turn — for instant equity.
  • Discount tainted outs: any card that could give an opponent a bigger hand isn't a full out.
  • Accurate out counts are the input for pot odds — get the count wrong and every later decision is wrong too.
Lesson test · 20 questions

Test yourself

Answer them all — 16/20 to pass. Every answer gets an explanation.

Question 1 / 20 Score 0

You hold four cards to a flush after the flop. How many outs do you have?

Review — all 20 questions & answers tap to expand
  1. You hold four cards to a flush after the flop. How many outs do you have?

    Answer 9

    A suit has 13 cards; with four already visible, nine remain to complete the flush.

  2. How many outs does an open-ended straight draw have?

    Answer 8

    Two ranks complete it, one on each end, and four cards of each rank make 8 outs.

  3. How many outs does a gutshot (inside) straight draw have?

    Answer 4

    Only one rank fills the hole, and there are four cards of that rank.

  4. You hold Ac Kd on a 9s 6h 2c flop. How many outs to pair one of your overcards?

    Answer 6

    Three aces plus three kings give you 6 outs to pair either overcard.

  5. You have a pocket pair that missed the flop. How many outs to make a set?

    Answer 2

    Two cards of your pair's rank remain in the deck, giving exactly 2 outs.

  6. Using the Rule of 4, a 9-out flush draw on the flop has roughly what equity to the river?

    Answer 36%

    9 outs times 4 is about 36%, a close estimate for two cards to come.

  7. Using the Rule of 2, a 9-out draw on the turn has roughly what equity?

    Answer 18%

    With one card to come you multiply outs by 2, giving about 18%.

  8. A combined flush draw and open-ended straight draw can have how many outs at most?

    Answer 15

    Nine flush outs plus eight straight outs, minus two cards that do both, equals about 15.

  9. What exactly is an 'out'?

    Answer An unseen card that improves your hand to a likely winner

    Outs are unseen cards that turn your hand into the probable best hand.

  10. A 'tainted' out is one that...

    Answer Improves your hand but could give an opponent a better hand

    A tainted out completes your hand but may also complete a bigger hand for someone else.

  11. You see four cards of your suit. How many flush outs remain?

    Answer 9

    13 cards per suit minus the 4 you can see leaves 9 outs.

  12. How many different ranks complete an open-ended straight draw?

    Answer 2

    An open-ender is completed by the rank above or below — two ranks, eight cards.

  13. Why should you sometimes discount your outs?

    Answer Because some outs may not actually give you the winning hand

    If an out can improve an opponent past you, counting it fully overstates your equity.

  14. A double gutshot (belly-buster) that can be filled by two different ranks has how many outs?

    Answer 8

    Two separate inside-straight holes each have four cards, totaling 8 outs like an open-ender.

  15. Using the Rule of 4, an 8-out straight draw on the flop is roughly what to hit by the river?

    Answer 32%

    8 outs times 4 gives about 32% equity with two cards to come.

  16. Each overcard that can pair contributes how many outs?

    Answer 3

    Three cards of that rank remain, so each unpaired overcard adds 3 outs.

  17. You hold 9h 8h on 7c 6d 2s. Which cards complete your straight?

    Answer Any 10 or any 5

    With 9-8-7-6 you make a straight with a 10 (top) or a 5 (bottom) — 8 outs.

  18. On the turn with one card to come, you multiply your outs by which number for a quick estimate?

    Answer 2

    The Rule of 4 and 2 uses times 2 when only the river remains.

  19. Which draw has the most outs?

    Answer Flush draw

    A flush draw's 9 outs beats overcards (6), gutshot (4) and set draws (2).

  20. Why is an accurate out count so important?

    Answer It determines the pot odds and equity your whole decision rests on

    Out counts feed directly into pot-odds math, so an error there corrupts every downstream decision.