How Many Straight Flushes Are There?

There are exactly 40 straight flushes in a standard 52-card deck — or 36 if you don’t count the four royal flushes as straight flushes. That’s out of 2,598,960 possible five-card hands, which is why a straight flush is the second-rarest hand in poker and lands near the very top of the ladder.

The quick count: 10 per suit, 4 suits

The math is refreshingly clean. A straight flush is five cards in sequence, all the same suit. Within a single suit, how many five-card runs are there?

Start with the lowest run and slide upward one card at a time:

• A-2-3-4-5 (the “steel wheel,” ace plays low)
• 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
• 10-J-Q-K-A (the royal flush, ace plays high)

That’s 10 sequences per suit. There are 4 suits, so:

10 sequences × 4 suits = 40 straight flushes.

Why the count stops at ten

A common mistake is to assume there are 13 straight flushes per suit (one for each rank). The catch is that a five-card run needs four cards above its bottom card. Once you reach 10-J-Q-K-A, there’s nowhere higher to go — poker straights don’t wrap from king through ace to two. So the top card of a straight flush is capped at the ace and the bottom card is capped at the 10. That leaves ten valid bottom cards (A through 10), hence ten runs.

Straight flushes vs. royals: the breakdown

Here’s how the 40 split, and where they sit on poker’s ten-hand ladder:

Add them: 4 royals + 36 plain straight flushes = 40. Because the royal is just the highest straight flush, some references list “straight flush: 40 combinations” and treat the royal as a subset; others list “36 straight flushes and 4 royal flushes” separately. Both are correct — they’re describing the same 40 hands. See how the two relate in our straight flush vs. four of a kind comparison and the full royal flush explainer.

The odds, worked out

Probability of any hand type is (ways to make it) ÷ (total five-card hands). There are C(52,5) = 2,598,960 distinct five-card hands.

• Any straight flush: 40 ÷ 2,598,960 = 0.00001539, or about 1 in 64,974.
• Royal flush only: 4 ÷ 2,598,960 = 0.00000154, or about 1 in 649,740.
• Straight flush excluding royals: 36 ÷ 2,598,960, or about 1 in 72,193.

To put that in perspective, a straight flush is roughly ten times rarer than four of a kind (which has 624 combinations), which is exactly why it outranks quads. If you want the full probability picture across every hand type, the poker hand probability chart is on the hub.

A worked count you can verify

Let’s count the spade straight flushes by hand to prove the “10 per suit” figure. Fix the suit as spades and list every valid bottom card:

• Bottom card A → A-2-3-4-5 ✓
• Bottom card 2 → 2-3-4-5-6 ✓
• Bottom card 3 → 3-4-5-6-7 ✓
• Bottom card 4 → 4-5-6-7-8 ✓
• Bottom card 5 → 5-6-7-8-9 ✓
• Bottom card 6 → 6-7-8-9-10 ✓
• Bottom card 7 → 7-8-9-10-J ✓
• Bottom card 8 → 8-9-10-J-Q ✓
• Bottom card 9 → 9-10-J-Q-K ✓
• Bottom card 10 → 10-J-Q-K-A ✓ (royal)
• Bottom card J → J-Q-K-A-? ✗ (no card above the ace)

That’s exactly 10 spade straight flushes, and the eleventh attempt fails because the ace has no successor. Multiply by 4 suits and you land on 40 every time.

Bottom line

There are 40 straight flushes in a 52-card deck — 10 sequences in each of the 4 suits, with the royal flush being the top one in each suit. Strip out the 4 royals and you’re left with 36 ordinary straight flushes. At roughly 1 in 65,000, it’s the second-rarest hand you can hold, sitting just below the royal on the hand rankings ladder. Brush up on what a run actually requires in our what is a straight guide, or dig into more counting in the odds and math hub.