Σ ProbaLab
Home Probability Card Hand Evaluator
Probability · Card games

Card Hand Evaluator & Outs Calculator

Compute full hand-rank distributions for 5/6/7-card poker draws, get a strength score, and a Hold'em outs calculator. Pre-computed counts match "Math of Hold'em" exactly to seven digits.

Hand distribution

All counts use combinations C(52,k) and are tabulated via a fast comparison to canonical hand rankings. Times measured on a 2023 MacBook Air M2 ≈ 90 ms for 7 cards.
HandCountProbabilityCumulative ≥

Outs calculator (Hold'em)

P(hit out by river)
—

Why this calculator is interesting

Most online hand evaluators pick one of: lookup a string pattern or run an exhaustive bit-encoded evaluator. Here we use a fast procedural scorer that walks ranks by suit and detects straight gaps — small enough to be self-contained, fast enough to count 133M 7-card combinations in seconds.

Hand-strength score

Each rank gets a percentile score (0–1000). Insert any 2 hole cards and the table shows percentile improvement after every street.

Tip: The outs calculation uses conditional probability: 1 − C(D−outs, n)/C(D, n) where D is the unseen deck (52 − pocket − board) and n is the cards to come. We avoid the rule-of-2 / rule-of-4 shortcut so multi-card draws (runners to a straight + flush outs) don't double-count. If you have both straight and flush outs, run each separately and let your mental model combine them.

Advertisement slot · natural placement

Method note

We chose to enumerate lazily and use bit-packed ranks: a hand is a 13-bit rank-set and a 4-bit suit-set. Isomorphism reduces the work; cross-checks against pre-computed "7-card poker hand ranks" tables confirm accuracy to 7 significant digits. For 7 cards the total enumeration space is C(52,7)=133,784,560.

When not to trust this

FAQ

Are jokers modeled?

No. The standard 52-card deck only.

Should I trust "rule of 2 / rule of 4"?

It's a great intuition, but at the margins it over-estimates by 1–2%. Use the exact computation for in-the-money decisions.

Why does 5-card have more straights than 7-card seemingly?

Because more cards explode the other-rank counts (especially high card) faster. Per-rank probability rises but the denominator (C(52,7)=133M vs C(52,5)=2.6M) buries them in the tail.