Poker Outs to Percentage Calculator
Convert your number of outs into the exact chance of hitting on the turn, the river or by the river — with the classic rule of 4 and 2 for comparison.
How it works
One card: P = outs ÷ unseen (47 on the flop, 46 on the turn) · Two cards: P = 1 − (47−outs)/47 × (46−outs)/46 · Rule of thumb: outs × 2 per card
After the flop there are 47 unseen cards from your perspective (52 minus your two hole cards and the three on board), so each out is worth 1 ÷ 47 ≈ 2.1% on the next card — the origin of the “rule of 2.” Seeing both the turn and river doubles your chances, roughly “rule of 4,” but the exact two-card figure is a little lower than 4 × outs because the two draws overlap. This tool gives the precise probability alongside the shortcut so you can see how good the mental estimate is.
Worked example
A flush draw has 9 outs. On the flop with two cards to come, the miss chance is (38/47) × (37/46) = 0.651, so you hit 34.9% of the time — the rule of 4 estimates 36%, close but slightly high. For just the turn card it is 9 ÷ 47 = 19.1%, matching the rule of 2’s 18%.
Frequently asked questions
What is an “out”?
An out is any unseen card that improves your hand to what you believe will be the winner. A flush draw has 9 outs (the remaining cards of your suit); an open-ended straight draw has 8. Discount outs that might make an opponent an even better hand.
Why is the rule of 4 slightly off?
Multiplying outs by 4 double-counts the small overlap between the turn and river draws. It slightly overestimates for large out counts — with 9 or more outs, subtract a point or two, or use the exact figure shown here.
Which street should I choose?
Use “flop → turn” or “turn → river” when you are only guaranteed to see one more card (for example facing a bet you may fold to). Use “flop → river” only when you will definitely see both cards, such as when you are already all-in.
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This calculator is for educational purposes. Double-check important results before acting on them.