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Poker Odds Calculator

Calculate the probability of completing a drawing hand in Texas Hold'em poker.

Reviewed by Christopher FloiedPublished Updated

This free online poker odds calculator provides instant results with no signup required. All calculations run directly in your browser — your data is never sent to a server. Enter your values below and see results update in real time as you type. Perfect for everyday calculations, homework, or professional use.

Cards remaining in the deck that complete your hand (e.g., 9 for a flush draw)

Unknown cards remaining (52 minus cards you have seen)

Results

Hit on Next Card

1914.9%%

Hit Within Two Cards

3496.8%%

Odds Against (One Card)

4.2 : 1

How to Use This Calculator

1

Enter your input values

Fill in all required input fields for the Poker Odds Calculator. Most fields include unit selectors so you can work in your preferred unit system — metric or imperial, whichever matches your problem.

2

Review your inputs

Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.

3

Read the results

The Poker Odds Calculator instantly computes the output and displays results with units clearly labeled. All calculations happen in your browser — no loading time and no data sent to a server.

4

Explore parameter sensitivity

Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.

Formula Reference

Poker Odds Calculator Formula

See calculator inputs for the governing equation

Variables: All variables and their units are labeled in the calculator interface above. Input fields accept values in multiple unit systems — select your preferred unit from the dropdown next to each field.

When to Use This Calculator

  • •Use the Poker Odds Calculator when you need accurate results quickly without the risk of manual computation errors or unit conversion mistakes.
  • •Use it to verify calculations made by hand or in spreadsheets — an independent check can catch errors before they lead to costly decisions.
  • •Use it to explore how changing input parameters affects the output — a quick way to develop intuition and identify the most influential variables.
  • •Use it when collaborating with others to ensure everyone is working from the same numbers and applying the same assumptions.

About This Calculator

The Poker Odds Calculator is a free, browser-based calculation tool for engineers, students, and technical professionals. Calculate the probability of completing a drawing hand in Texas Hold'em poker. It implements standard formulas and supports both metric (SI) and imperial unit systems with automatic unit conversion. All calculations are performed instantly in your browser with no data sent to a server. Use this calculator as a quick reference and sanity-check tool during design, analysis, and learning. Always verify results against primary engineering references and applicable standards for any safety-critical application.

About Poker Odds Calculator

The Poker Odds Calculator computes the probability of completing a drawing hand in Texas Hold'em poker. By entering the number of outs (cards that improve your hand) and the cards remaining in the deck, you can calculate the exact probability of hitting your draw on the next card or within the next two cards. Understanding pot odds versus drawing odds is fundamental to making profitable poker decisions.

The Math Behind It

Poker odds are based on combinatorics and probability theory. An out is any unseen card that, if dealt, would give you a winning hand. The probability of hitting an out equals the number of outs divided by the number of unknown cards remaining. In Texas Hold'em after the flop, you have seen 5 cards (2 hole cards + 3 community cards), leaving 47 unknown cards. After the turn, 46 remain. The probability of hitting on the next card is simply outs/remaining. For two cards, you calculate the probability of missing both and subtract from 1. Common drawing situations have well-known out counts: a flush draw has 9 outs (13 cards of the suit minus 4 you see), an open-ended straight draw has 8 outs, a gutshot straight draw has 4 outs, and a combination flush-and-straight draw can have up to 15 outs. The "Rule of 2 and 4" provides a quick mental approximation: multiply your outs by 2 for the percentage chance of hitting on the next card, or by 4 for the percentage chance of hitting within two cards. For 9 outs: 9 * 2 = 18% (actual: 19.1%) or 9 * 4 = 36% (actual: 35.0%). Pot odds compare the cost of a call to the size of the pot. If the pot offers better odds than your drawing odds, calling is mathematically profitable in the long run. This expected value calculation is the foundation of strategic poker.

Formula Reference

Drawing Probability

P(one card) = outs / remaining, P(two cards) = 1 - ((R-O)/R * (R-1-O)/(R-1))

Variables: O = outs, R = remaining cards in deck

Worked Examples

Example 1: Flush draw on the flop

You have two hearts and the flop shows two hearts (9 outs for a flush), with 47 cards remaining.

Step 1:One card probability: 9 / 47 = 19.1%
Step 2:Two card probability: 1 - (38/47 * 37/46) = 1 - 0.650 = 35.0%
Step 3:Odds against (one card): (47 - 9) / 9 = 4.2 : 1

You have a 19.1% chance of hitting on the turn and a 35.0% chance of hitting by the river. You need pot odds better than 4.2:1 to call profitably on the turn.

Common Mistakes & Tips

  • !Counting outs that would also improve an opponent's hand to a better hand than yours.
  • !Using the two-card probability when facing a bet on the turn, when you should use the one-card probability.
  • !Forgetting to compare drawing odds to pot odds before deciding to call.

Related Concepts

Password Entropy Calculator

Both use combinatorics and probability calculations to evaluate outcomes.

Frequently Asked Questions

What is the Rule of 2 and 4?

A quick estimation method: multiply your outs by 2 for the percentage chance with one card to come, or by 4 with two cards to come. For 9 outs, this gives 18% and 36%, close to the actual values of 19.1% and 35.0%.

How do I count outs?

Count cards remaining in the deck that complete your hand. Flush draw: 9 outs (13 of your suit minus 4 seen). Open-ended straight: 8 outs. Gutshot straight: 4 outs. Pair to trips: 2 outs. Adjust down for cards that might give opponents a better hand.