Flush Draw Odds: Exact Probability for Every Street

Last updated: April 30, 2026

A flush draw in Texas Hold'em has 9 outs and hits approximately 35% of the time by the river when seen from the flop, or 19.6% on the river alone when you're on the turn. Below is the complete probability breakdown, comparison table, and decision guidance.

Flush Draw Probability by Street

The table below shows the exact probability of completing a standard flush draw (9 outs) on each street, alongside the Rule of 4 & 2 approximation.

Situation	Outs	Approx (Rule)	Exact %
Flop → River (2 cards to come)	9	9 × 4 = 36%	35.0%
Turn → River (1 card to come)	9	9 × 2 = 18%	19.6%
On the flop (just the turn card)	9	9 × 2 = 18%	19.1%

How to Count Flush Draw Outs

Counting flush outs is straightforward: a standard deck has 13 cards of each suit. Subtract the cards of your suit that are visible (your two hole cards + community cards of that suit). The remaining cards are your outs.

Example

You hold 9♥ 8♥. Board: K♥ 7♥ 2♣.

Total hearts in a deck: 13
Hearts you can see: 9♥, 8♥, K♥, 7♥ = 4 hearts
Remaining hearts in the unseen deck: 13 − 4 = 9 outs
Flop equity: 9 × 4 = 36% (exact: 35.0%)

Important: If you also hold a card of your suit in your hand (e.g., you hold J♥ and the board has one heart), you still have 9 outs — the logic doesn't change. But if the board has 3 or more of your suit, you already have a flush — no draw needed.

When to Call with a Flush Draw

Compare your flush draw equity to the pot odds required to call. If your equity exceeds the pot odds percentage, calling is mathematically profitable long-term.

Bet Size (vs pot)	Pot Odds Required	Flop (35%)	Turn (19.6%)
¼ pot	20%	✅ Call (+EV)	✅ Call (+EV)
½ pot	25%	✅ Call (+EV)	✅ Call (+EV)
⅔ pot	29%	✅ Call (+EV)	❌ Fold (−EV)
1× pot	33%	✅ Call (+EV)	❌ Fold (−EV)
2× pot	40%	❌ Fold (−EV)	❌ Fold (−EV)

Note: implied odds may justify calling when marked as −EV above, especially in deep-stacked games where hitting your flush earns additional bets on later streets.

Flush Draw vs Other Draws

A flush draw is one of the strongest single draws in Texas Hold'em — second only to open-ended straight draws in outs, and significantly stronger than gutshots.

Draw Type	Outs	Flop → River	Turn → River	Strength
→ Flush draw	9	35.0%	19.6%	Strong
Open-ended straight draw	8	31.5%	17.4%	Strong
Flush draw + gutshot (combo)	12	45.0%	26.1%	Very strong
Flush draw + open-ender (combo)	15	54.1%	32.6%	Dominant
Gutshot straight draw	4	16.5%	8.7%	Weak
Two overcards	6	24.1%	13.0%	Marginal

Definitions

Flush Draw

Holding four cards of the same suit with one more needed to complete a flush. Also called a 'four-flush'.

Outs

The number of unseen cards that will complete your drawing hand. A flush draw has 9 outs (13 of a suit minus 4 already seen).

Backdoor Flush Draw

A draw that needs two consecutive cards of your suit — one on the turn and one on the river. Probability ~4.2% from the flop.

Combo Draw

Holding a flush draw and a straight draw simultaneously. A flush draw + open-ender has up to 15 outs (~54% equity from the flop).

Frequently Asked Questions

What are the odds of hitting a flush draw on the river?

If you have a flush draw after the turn (one card to come), the probability of hitting your flush on the river is approximately 19.6% — roughly 1 in 5. The Rule of 2 gives a quick estimate: 9 outs × 2 = 18%, which is close to the exact figure.

What are the odds of hitting a flush draw by the river (from the flop)?

With two cards to come (flop to river), a flush draw hits approximately 35.0% of the time — a little more than 1 in 3. The Rule of 4 gives 9 × 4 = 36%, slightly overestimating due to card overlap.

How many outs does a flush draw have?

A standard flush draw has 9 outs. There are 13 cards of each suit in a deck. If you hold two hearts and two hearts are on the board, 4 hearts are accounted for — the remaining 9 hearts in the unseen deck each complete your flush.

Is a flush draw worth calling a pot-sized bet?

No — not on the turn. A pot-sized bet requires 50% pot odds, and your flush draw equity is only ~19.6% on the turn. You need pot odds of roughly 1 in 5 (about 20%) or better to call profitably. A flush draw on the flop (35% equity) can justify calling larger bets, but you should also factor in implied odds and position.

What is a backdoor flush draw?

A backdoor flush draw (also called runner-runner flush) requires two more cards of your suit to appear — one on the turn and one on the river. The odds are approximately 4.2% from the flop. This is far weaker than a standard flush draw and should rarely be the primary reason to call a bet.

Does a flush draw beat a pair?

A made flush beats two pair, three of a kind, a straight, and anything below. But a flush draw is not a made hand — you only hold the potential. Against a made flush, a flush draw loses unless you hit a higher flush. Against top pair, your flush draw gives you roughly 35% equity from the flop — meaning top pair is still a 65% favorite.

What is the rule of 4 and 2 for flush draws?

The Rule of 4 & 2 is a quick shortcut: multiply your outs by 4 on the flop (two cards to come) or by 2 on the turn (one card to come). For a flush draw: 9 outs × 4 = 36% from the flop, 9 outs × 2 = 18% from the turn. The exact figures are 35.0% and 19.6% respectively.

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