Straight Flush Probability: 1 in 72,193

By Vinoth Kanna · 31 July 2026

Poker Math · Probability

There are exactly 36 non-royal straight flushes in a 52-card deck. Against the 2,598,960 possible five-card hands that’s 0.00139%, or 1 in 72,193 — the second-rarest hand in poker, beaten only by the royal flush itself.

Count the four royals as straight flushes too (they are — a royal is just the ace-high version) and you get 40 combinations, or 1 in 64,974.

Where the 36 comes from

A straight flush is five cards in sequence, all the same suit. It’s fully defined by two things: its high card and its suit.

Valid high cards: 9. A five-card sequence can top out at 5, 6, 7, 8, 9, 10, J, Q, or K. The 5 is legal because A-2-3-4-5 counts as a straight with the ace playing low. Ace-high would be A-K-Q-J-10 — that’s a royal flush, counted separately.

Suits: 4.

9 high cards × 4 suits = 36 straight flushes

Add the 4 ace-high ones and there are 40 straight flushes in total. This is also why the plain-flush and plain-straight counts subtract 40: 5,148 suited five-card sets minus 40 = 5,108 flushes; 10,240 sequences minus 40 = 10,200 straights. Every hand gets counted once, at its highest ranking. The full derivation for all ten hands is in poker hand probabilities.

Straight flushes are about 17 times rarer than quads, which is why they sit above them on the hand rankings.

The 36 hands, listed

Nine per suit, top card in bold:

• A-2-3-4-5 (the “steel wheel”)
• 2-3-4-5-6
• 3-4-5-6-7
• 4-5-6-7-8
• 5-6-7-8-9
• 6-7-8-9-10
• 7-8-9-10-J
• 8-9-10-J-Q
• 9-10-J-Q-K

Times four suits. The tenth sequence — 10-J-Q-K-A — is the royal flush.

The steel wheel: A-2-3-4-5 suited

The lowest straight flush is A-2-3-4-5 of one suit, universally called the “steel wheel” (a plain A-2-3-4-5 is “the wheel”). The ace plays low here, and the 5 is the hand’s high card.

That matters because straight flushes are compared by high card, so the steel wheel loses to every other straight flush — including 2-3-4-5-6 suited, whose high card is a 6. New players routinely misplay this, assuming the ace makes their straight flush the big one. It doesn’t. Ace-low means five-high.

The one thing an ace cannot do is wrap around. Q-K-A-2-3 is not a straight and never a straight flush, in any standard game. The ace sits at one end or the other, never in the middle.

Comparing two straight flushes

Highest top card wins. That’s the entire rule.

• 9-10-J-Q-K suited beats 8-9-10-J-Q suited (king-high beats queen-high).
• 2-3-4-5-6 suited beats A-2-3-4-5 suited (six-high beats five-high).
• Two straight flushes with the same top card in different suits split the pot — suits do not break ties in standard poker.

The split scenario is nearly theoretical in Hold’em, where a straight flush needs at least three suited connected community cards, and both players would need to make the identical sequence from different holdings. It’s more plausible in seven-card stud, where two players hold entirely separate cards — and it’s still a chop.

How often it happens in Hold’em

Seven cards beat five. Of the 133,784,560 seven-card combinations:

So roughly one hand in 3,200 taken to the river is a straight flush. In a 30-hands-per-hour live game where you actually see maybe a fifth of rivers, that’s a few times a year. Online at four tables, several times a month.

Flopping one is the same 1 in 64,974 as the five-card figure — flopping a straight flush means five specific cards, your two plus the flop, form it, and that’s identical to being dealt them. The order doesn’t change the math.

Drawing to one is where the practical value lives. A flopped open-ended straight flush draw — say you hold 8♥9♥ on a 6♥7♥2♣ flop — has:

• 15 outs to make a flush or straight: 54.1% by the river. You are a favorite against most made hands.
• 2 outs to the straight flush itself (the 5♥ and the 10♥): 8.4% by the river.

Play those hands for the 54%, not the 8.4%. The straight flush is a bonus; the flush and straight equity is the reason you’re in the pot. Run a few of these through the free odds calculator and the sizing decisions become obvious.

The danger: second-nut straight flush

A straight flush is unbeatable except by a higher straight flush — and the board texture required to make one makes higher ones simultaneously possible. This is the coldest cooler in poker, and it’s worth understanding before it happens to you.

The setup. Board: 7♦ 8♦ 9♦. You hold 5♦ 6♦ — a nine-high straight flush, flopped. You are never folding.

The problem. Anyone holding 10♦-J♦ has a jack-high straight flush. Anyone holding 10♦ with another diamond in the 6-10 range has a ten-high straight flush. Both beat you, and both are exactly the kind of suited-connector hand that plays these boards.

The signal is simple: when three connected suited cards hit the board, your straight flush is only the nuts if you hold the top end of the sequence. With 5♦6♦ on 7♦8♦9♦ you have the bottom end. With 10♦J♦ you’d have the top end and genuinely be unbeatable (barring the Q♦K♦ that doesn’t complete anything here).

Practical takeaways:

• Know whether you have the top end before the money goes in. It takes two seconds and it’s the only defensive read available.
• You still stack off. The frequency of the bottom-end straight flush running into the top-end one is so low that folding would be a much larger error than paying it off. Second-nut straight flushes lose money once a decade; folding them loses money every time.
• Suited connectors are the culprit on both sides. Hands like 6-7s and 8-9s make these, and they make them against each other. That’s not a reason to stop playing them.

The identical logic applies one rank down: a full house on a paired board is often the second-best full house, and that costs far more players far more money than straight flushes ever will — because it happens constantly.

Quick answers

• How many straight flushes are there? 36 non-royal, 40 including royals.
• What are the odds of a straight flush? 1 in 72,193 for five cards; about 1 in 3,590 across seven cards in Hold’em.
• What beats a straight flush? Only a higher straight flush, of which the royal flush is the highest.
• Is A-2-3-4-5 suited a straight flush? Yes — the lowest one. The 5 is the high card.
• Is Q-K-A-2-3 suited a straight flush? No. Straights never wrap around.
• Does a straight flush beat four of a kind? Yes — quads are 17 times more common.

For how the rest of the chart is ordered by rarity, see does a flush beat a straight.

Keep learning: try the free poker odds calculator, memorize the hand rankings, or browse all strategy guides.