# Poker Odds Calculator

Calculate Texas Hold'em poker odds from your outs. Get turn, river, and combined probabilities plus the Rule of 2 and 4 approximation.

## What this calculates

Enter your number of outs to instantly calculate your probability of hitting on the turn, river, or both. Uses exact probabilities and the popular Rule of 2 and 4 shortcut.

## Inputs

- **Number of Outs** — min 1, max 47 — Cards remaining in the deck that complete your hand (e.g., 9 outs for a flush draw).
- **Cards to Come** — options: One card (turn or river only), Two cards (turn + river) — How many community cards are still to be dealt.

## Outputs

- **Turn Odds (Next Card)** — formatted as percentage — Probability of hitting on the next single card.
- **River Odds (Last Card)** — formatted as percentage — Probability of hitting on the river card alone.
- **Combined Odds (Turn + River)** — formatted as percentage — Probability of hitting on at least one of the two remaining cards.
- **Rule of 2/4 Approximation** — formatted as percentage — Quick mental math approximation (outs x 2 or outs x 4).
- **Odds Against** — formatted as text — Expressed as X:1 against hitting your hand.
- **Calculation** — formatted as text — Step-by-step breakdown of the odds calculation.

## Details

**How Poker Outs Work**

An "out" is any unseen card that completes your hand. After the flop, 47 unknown cards remain (52 minus your 2 hole cards minus 3 community cards).

**Exact Formulas:**

- **Turn odds** = Outs / 47
- **River odds** = Outs / 46
- **Combined odds** = 1 - ((47 - Outs)/47) x ((46 - Outs)/46)

**The Rule of 2 and 4**

A fast mental shortcut used at the table:

- **One card to come:** Multiply outs by 2 for approximate percentage
- **Two cards to come:** Multiply outs by 4 for approximate percentage

This approximation is surprisingly accurate for 1 to 15 outs.

**Common Out Counts:**

| Draw | Outs | ~Turn+River % |
|------|------|---------------|
| Flush draw | 9 | ~35% |
| Open-ended straight | 8 | ~31% |
| Gutshot straight | 4 | ~17% |
| Two overcards | 6 | ~24% |
| Set from a pair | 2 | ~8% |

## Frequently Asked Questions

**Q: How do I count my outs in poker?**

A: Count every unseen card that would complete your winning hand. For a flush draw after the flop, you have 4 suited cards showing and need one more, so 13 total of that suit minus 4 = 9 outs. For an open-ended straight draw, you have 8 outs (4 cards on each end).

**Q: Why is the Rule of 4 not perfectly accurate?**

A: The Rule of 4 is a linear approximation that overestimates slightly as outs increase. With 9 outs, Rule of 4 gives 36% while the exact value is about 35%. The error grows for high out counts, but for most practical situations (under 15 outs) it stays within a few percentage points.

**Q: Should I use turn odds or combined odds?**

A: Use combined odds (two cards to come) only when you are deciding to call an all-in on the flop, because both remaining cards are guaranteed. If your opponent can bet again on the turn, use single-card (turn only) odds for your flop decision, since you may face another bet before seeing the river.

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Source: https://vastcalc.com/calculators/statistics/poker-odds
Category: Statistics
Last updated: 2026-04-08