Poker Outs Calculator: Counting Outs and the Rule of 4 and 2
Last updated: June 17, 2026
An out is any unseen card that improves your hand into a likely winner. To turn a count of outs into a percentage, use the rule of 4 and 2: on the flop, with two cards still to come, multiply your outs by 4 to estimate your chance of hitting by the river; on the turn, with one card to come, multiply your outs by 2. A flush draw has 9 outs, which is about 35% to complete by the river (9 × 4 ≈ 36%) and about 19.6% to hit on the river from the turn (9 × 2 = 18%).
The rule is a fast mental shortcut, not an exact figure. The rule of 2 (one card to come) is within half a percent of the true number; the rule of 4 (two cards to come) slightly overestimates large draws because it double-counts hands that hit twice. This guide gives the full outs reference table from 1 to 15 outs, the exact probabilities behind each figure, and a calculator to confirm any spot precisely.
What Are Outs in Poker?
An out is a card still in the deck that turns your hand into a winner. After the flop, there are 47 cards you cannot see — 52 in the deck minus your two hole cards and the three board cards. From the turn, 46 cards are unseen. Your outs are the subset of those unseen cards that complete or improve your hand to the best one at the table.
Counting starts by identifying the draw. If you hold two hearts and two more hearts are on the flop, you have four cards to a flush and there are nine hearts left — nine outs. If you hold an open-ended straight draw, two distinct ranks complete it, giving four cards each, or eight outs. A gutshot has one rank that completes it, giving four outs.
The hardest part is counting only clean outs. A card that gives you a straight but also puts a third flush card on the board may hand an opponent a stronger hand — that out is tainted and should be discounted, often counted as half an out. Overcounting outs is the single most common reason players make losing calls.
The Rule of 4 and 2 Explained
The rule of 4 and 2 converts outs into a quick percentage. With two cards still to come (you are on the flop), multiply outs by 4. With one card to come (you are on the turn), multiply outs by 2. The result approximates your chance of improving.
Flop (2 cards to come): chance ≈ outs × 4
Turn (1 card to come): chance ≈ outs × 2
Why these multipliers? On the turn, one card is dealt from 46 unseen cards, so each out is worth 1 ÷ 46 ≈ 2.17% — close to 2 per out. On the flop, two cards are dealt, so the chance roughly doubles, hence ×4. The flop multiplier is an overestimate for large draws because it counts the runouts that hit on both streets twice. For draws above about 8 outs, subtract the amount your outs exceed 8 to correct it: 13 outs → 13 × 4 = 52, minus 5 = 47%, against an exact 48.1%.
The rule of 2 needs no correction — it tracks the exact figure within half a percent across every out count. Use the rule for live decisions and the table below to memorize the common spots.
Poker Outs Chart — 1 to 15 Outs
This table lists every common out count alongside the exact probabilities. The Turn % column is your chance to hit on the river with one card to come (matches the rule of 2). The Flop % column is your exact chance to hit by the river with two cards to come; the Rule of 4 column is the ×4 approximation for comparison.
Note how the Rule of 4 column tracks the exact Flop % closely up to about 8–9 outs, then begins to overstate it. At 15 outs the rule gives 60% against an exact 54.1% — a 6-point overestimate. For large combo draws, lean on the exact figure or apply the −(outs − 8) correction.
Outs & Equity Calculator
Use the RiverOdds calculator below to confirm any draw exactly. Enter your hole cards and the board, and it computes your precise equity by enumerating every remaining runout — no rule-of-4-and-2 approximation, no rounding error. Compare the result to your hand-counted outs to check whether you are counting clean.
How to use for outs: (1) Enter your hole cards and the flop or turn. (2) Read the displayed equity — that is your true chance to win. (3) Count your outs by hand and apply the rule of 4 or 2. (4) Compare the two; a large gap usually means you counted a tainted out as clean.
How to Count Outs Step by Step
Counting outs accurately is more important than the arithmetic that follows. Work through these steps for any drawing hand:
Step 1: Name the hand you are drawing to
Decide what hand you need — a flush, a straight, a set, two pair — and which exact cards complete it.
Step 2: Count every card that completes it
Flush draw: 9 cards of the suit. Open-ended straight: 8 (four on each end). Gutshot: 4. Two overcards: 6 (three of each rank).
Step 3: Remove tainted outs
If an out also completes a likely opponent draw — for instance a straight card on a two-flush board — discount it, often counting it as half an out.
Step 4: Apply the rule of 4 or 2
Two cards to come (flop): outs × 4. One card to come (turn): outs × 2. That is your approximate chance to hit.
Worked Example
You hold 9♥ 8♥ on a flop of K♥ 7♠ 2♥. You have a flush draw (9 hearts left) plus a gutshot to the straight is not present here, so 9 clean outs. Two cards to come: 9 × 4 = 36%, close to the exact 35.0%. If a 6♥ or 10♥ on a later board would also pair the board into a possible full house for an opponent, you would shade that estimate down — but on this dry flop, the 9 outs are clean.
Common Draws and Their Outs
Memorizing the out count for the standard draws removes most of the counting work at the table. These are the spots you will face most often.
Flush draw
9 outs
≈ 35% by river (flop) · 19.6% (turn)
Open-ended straight
8 outs
≈ 31.5% by river (flop) · 17.4% (turn)
Gutshot straight
4 outs
≈ 16.5% by river (flop) · 8.7% (turn)
Two overcards
6 outs
≈ 24.1% by river (flop) · 13.0% (turn)
Set to full house / quads
7 outs
≈ 27.8% by river (flop) · 15.2% (turn)
Flush + open-ended (combo)
15 outs
≈ 54.1% by river (flop) · 32.6% (turn)
Definitions
Frequently Asked Questions
What are outs in poker?
An out is any unseen card remaining in the deck that improves your hand into one that is likely to win. If you hold four cards to a flush after the flop, there are nine cards of that suit still unseen — so you have nine outs. Counting outs is the first step in estimating your equity: more outs means a higher chance of completing your draw on the next card or by the river. Outs are counted from the cards you cannot see, which on the flop is 47 (52 minus your 2 hole cards and the 3 board cards). You should count only clean outs — cards that genuinely give you the best hand. A card that completes your straight but also puts a third flush card on the board for an opponent is not a clean out.
What is the rule of 4 and 2?
The rule of 4 and 2 is a shortcut for converting outs into an approximate percentage chance of hitting your draw. On the flop, with two cards still to come (turn and river), multiply your outs by 4 to estimate your chance of improving by the river. On the turn, with only one card to come (the river), multiply your outs by 2. Example: a flush draw has 9 outs. On the flop, 9 × 4 = 36%, which is close to the exact 35.0%. On the turn, 9 × 2 = 18%, close to the exact 19.6%. The rule trades a small amount of accuracy for speed you can use at the table without a calculator.
How accurate is the rule of 4 and 2?
The rule of 2 (turn, one card to come) is very accurate — it is within roughly half a percent of the exact figure across all out counts. The rule of 4 (flop, two cards to come) is accurate for small draws but drifts higher than reality as outs increase, because it double-counts the cases where you would hit on both the turn and the river. At 9 outs the rule of 4 gives 36% versus the exact 35.0% — close enough. At 15 outs it gives 60% versus the exact 54.1% — an overestimate of about 6 points. A common correction for large draws (around 9+ outs) is to subtract the amount your outs exceed 8: for 13 outs, 13 × 4 = 52, minus (13 − 8) = 5, giving 47%, much closer to the exact 48.1%.
How many outs does a flush draw have?
A flush draw has 9 outs. There are 13 cards of each suit in the deck. If you hold two of one suit and two more of that suit are on the board, that accounts for 4 cards, leaving 9 cards of the suit unseen. Each of those 9 cards completes your flush. Using the rule of 4 and 2: on the flop a flush draw is about 35% to complete by the river (9 × 4 ≈ 36%), and on the turn it is about 19.6% to hit on the river (9 × 2 = 18%).
How many outs does an open-ended straight draw have?
An open-ended straight draw (also called a two-way or open-ended straight draw) has 8 outs. You have four cards to a straight that can be completed on either end — for example holding 8-7 on a 6-5-2 board, any 9 or any 4 completes the straight. There are four 9s and four 4s in the deck, so 8 outs total. On the flop that is about 31.5% to complete by the river (8 × 4 = 32%); on the turn it is about 17.4% to hit the river (8 × 2 = 16%). A gutshot (inside) straight draw, by contrast, has only 4 outs because it can be completed by one rank rather than two.
What is the difference between outs and equity?
Outs are the count of specific unseen cards that improve your hand. Equity is your overall percentage share of the pot across every possible remaining runout — it accounts for ties, the chance your improvement still loses, and any equity you have even when you do not improve. The rule of 4 and 2 converts outs into an approximate equity estimate, but it assumes every out gives you the winning hand and that you have no equity otherwise. For an exact number, an odds calculator enumerates every possible board rather than relying on the approximation.
Should I count all my outs as equal?
No — count only clean outs. A clean out is a card that improves you to a hand that almost certainly wins. Discount outs that complete your hand but also improve a likely opponent holding. For example, if you have an open-ended straight draw on a two-flush board, some of your straight cards may also complete an opponent's flush — those are not full outs. A practical adjustment is to count tainted outs as half an out. Counting outs accurately matters more than the rule-of-4-and-2 arithmetic: overcounting outs is the most common reason players talk themselves into bad calls.
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