Odds Calculator
A practical tool that works out how often your draw completes, and whether a call is worth it. There are two modes: work from a template, where you just pick a common draw, and your win rate against a given number of players, which comes from work from cards using your actual hole cards and board.
Pick the shape of your handThis number of outs feeds straight into the completion rate below. More outs means a higher chance of getting there.
From which point?Decide whether to call on the flop using the "2 cards to come" number. Once the turn is out, switch to the "1 card to come" number and decide again whether to call to the river.
Result
Chance of completing your flush draw: 35.0%(about 1 in 2.9)
The "rule of 2 and 4" estimate: 36%(9 outs × 4)
Is the call worth it? (pot odds)The "equity needed" is the minimum win rate at which this call does not lose money in the long run. How it is worked out is explained in the pot odds section below.
Equity needed for the call to break even: 16.7%＝ 200 ÷（1,000＋200）
Your chance of completing: 35.0%
This is a call (your chance of completing beats the equity needed)
Terms and ideas
Outs
The number of cards left that complete your hand
There is no fixed number per shape. You count how many cards of the rank or suit you need are still in the deck, every time
e.g.With a flush draw: 13 cards share the suit. Take away the 4 you can see (2 in hand, 2 on the board) and 9 are left, so you have 9 outs
Each template under "Pick the shape of your hand" also shows how its outs are counted
The rule of 2 and 4 (for quick mental maths)
Chance of completing on the next card ≈ outs × 2%
Chance of completing from the flop to the river (2 cards) ≈ outs × 4%
e.g.A flush draw on the flop (9 outs) → 9 × 4 = about 36%
Up to about 12 outs, this stays within 1-2% of the exact figure
Pot odds (is the call worth it?)
Equity needed = call ÷ (pot + call)
This finds the win rate at which what you gain when you win exactly cancels what you lose when you do not. Win more often than that and, repeated over time, you come out ahead
e.g.Calling 200 into a pot of 1,000 → 200 ÷ 1,200 = 16.7%. Winning 16.7% × 1,000 = 167 and losing 83.3% × 200 = 167 balance exactly at that point
If your chance of completing beats the equity needed, calling pays in the long run
Whether a raise is good also depends on how often they fold (fold equity), which no simple formula covers. Pot odds are primarily for call decisions. Read more in
How the number of players affects the odds
Your chance of completing does not change with the number of players (you cannot see their cards, so they are no different from the deck)
Your win rate falls as more players join, because someone is more likely to hold a stronger hand
Win rate with the player count factored in is calculated in "From cards" mode
A draw that completes 35% of the time misses two times out of three. The gap between the number and how it feels only closes once you have chased a few of them.
Try it out in Poker Online.