Cribbage Calculator

The Cribbage Calculator calculates hand and crib scores, highlights fifteens, pairs, runs, and suggests optimal discards and pegging moves.

About the Cribbage Calculator

The Calculator evaluates a standard five-card scoring set (your four cards plus the cut card), the crib, or a full pegging sequence. It applies official scoring rules: fifteens, pairs and multiples, runs (including double and triple runs), flushes, and “his nobs.” For pegging, it tracks the running total to 31 and awards points for 15, 31, pairs, three- and four-of-a-kind, runs, “go,” and last card.

You can enter exact cards and get a step-by-step breakdown, or run simulations when the cut card is unknown. The tool outputs your score with labeled components and a concise explanation of how each point was derived. Optional settings align with common house rules, such as crib flush requirements and muggins (claiming missed points). The result section is designed for clarity, so you can verify and learn from each scoring line.

How to Use Cribbage (Step by Step)

Cribbage is played with a standard 52-card deck. Each player is dealt six cards in two-player games, discards two to the crib, and then plays out cards in turn to a running total that cannot exceed 31. After pegging, both players count their hands plus the cut card; the dealer also counts the crib. The first to reach 121 points on the board wins.

• Deal and discard: Each player gets six cards and discards two to form the crib (a bonus hand for the dealer).
• Cut: The non-dealer cuts the deck to reveal the cut card used in all hands’ scoring.
• Pegging: Players alternately lay one card, adding to a running total up to 31, scoring for 15, 31, pairs, and runs.
• Counting hands: Non-dealer counts and scores the hand first, then the dealer counts and scores the hand and the crib.
• Winning: Peg and count until someone reaches 121 points; score exactly and announce points as earned.

Cribbage rewards both tactics and math. The discard choice affects crib value, pegging creates tactical scoring windows, and the final hand count depends on how well you assemble fifteens, runs, and pairs. Practice careful counting and seek runs and 15s while watching what your opponent holds back.

Cribbage Formulas & Derivations

The Calculator follows deterministic scoring formulas. It treats ranks as A=1, 2–10 face value, and J/Q/K=10 when counting to 15. Cards are sets of rank and suit. Below are the foundations it uses to compute each scoring component from a set of five cards (your four plus the cut) or from pegging sequences.

• Fifteens: Any subset of cards whose values sum to 15 scores 2 points. The Calculator enumerates all subsets. Example: {5, 5, 5} makes one fifteen; each {5, J/Q/K/10} makes a fifteen. Total 15s × 2 = points from fifteens.
• Pairs and multiples: For each rank appearing k times, points = 2 × C(k, 2) where C denotes combinations. A pair (k=2) scores 2; three of a kind (k=3) scores 6; four of a kind (k=4) scores 12.
• Runs: Sort ranks and examine contiguous sequences of length ≥ 3. If there are duplicates in any rank within the span, multiplicity multiplies runs. For a span of distinct ranks r1–rL, score = L × (product of counts of each rank within the span). Example: 3-4-5 with duplicated 4 yields 2 runs of 3 for 6 points.
• Flush: In hand counting, four cards of the same suit score 4; if the cut card shares the suit, score 5. In crib counting, the flush scores only if all five cards share suit (5 points).
• His nobs: A jack in hand matching the cut card’s suit scores 1 point.
• Pegging: 15 scores 2; 31 scores 2; last card scores 1 (unless it is also 31). Pairs in immediate sequence score 2; three-of-a-kind scores 6; four-of-a-kind scores 12. Runs score length × 1 when the last laid card completes a consecutive sequence, with ranks counted uniquely but allowing duplicates to extend multiplicity over successive plays.

These rules are additive and independent: the Calculator identifies all 15s, all pairs/multiples, all distinct runs with multiplicity, plus flush and nobs. During pegging it tracks order, prevents totals beyond 31, and awards points immediately upon completion of a pattern. Optional features can toggle house-rule exceptions, but standard scoring is the default.

What You Need to Use the Cribbage Calculator

Gather a few details before you start. The Calculator can compute a single hand, a crib, a pegging round, or run what-if analyses. Clear inputs ensure accurate results and easy verification.

• Your four-card hand (rank and suit for each card).
• The cut card (or choose “unknown” to simulate outcomes).
• Who is dealer (affects crib ownership and counting order).
• Crib owner (dealer by default), and whether you are scoring hand or crib.
• Pegging sequence (ordered list of plays in a count-to-31 round).
• House rules: muggins on/off, crib flush enforcement, and target score (typically 121).

Inputs must represent a real deck: no duplicate cards and valid ranks/suits. Pegging sequences may reset to 0 after a “go,” and each subtotal must be ≤ 31. The tool enforces crib flush rules (five-card uniform suit required for a crib flush). When simulating an unknown cut, results appear as probabilities and expected values, not single totals.

Step-by-Step: Use the Cribbage Calculator

Here’s a concise overview before we dive into the key points:

1. Select the mode: Hand, Crib, Pegging, or Simulation.
2. Enter your four cards and, if known, the cut card.
3. Choose dealer and crib owner, and set any house rules.
4. If pegging, enter the sequence of plays in order.
5. Click Calculate to compute the score.
6. Review the step-by-step breakdown for fifteens, pairs, runs, nobs, flush, and pegging points.

These points provide quick orientation—use them alongside the full explanations in this page.

Case Studies

Case 1: Maximum hand example. Hand: 5♥, 5♦, 5♣, J♣. Cut: 5♣. Fifteens: four ways (each 5 with J♣) for 8 points, plus four ways (any three 5s) for 8 points; total 16. Pairs: C(4,2)=6 for 12 points. His nobs: J♣ matches cut suit for 1 point. Result: 16 + 12 + 1 = 29 points in hand. Interpretation: This rare hand demonstrates multiplicity of 15s and pairs.

What this means: The Calculator confirms all 15s, pairs, and nobs to reach the famous 29-point result.

Case 2: Pegging sequence with runs and 31. Opponent leads 6 (count 6). You play 7 (13). Opponent plays 8 (21) and scores 3 for the 6-7-8 run. You play 9 (30) and score 4 for the 6-7-8-9 run. Opponent cannot play without exceeding 31 and says “go.” You play A (1) to reach 31 and score 2. Result: Opponent scores 3; you score 6 total (4 for the run, 2 for 31). Interpretation: Building on a run can outscore an earlier, shorter run in the same sequence.

What this means: The Calculator tallies immediate run points to the card that completes each run and awards 31 correctly.

Accuracy & Limitations

The Calculator implements standard cribbage rules and counts every scoring component deterministically. For simulations with unknown cards, it uses unbiased sampling from the remaining deck. The output notes each component so you can verify the count yourself. Still, there are practical limitations you should know.

• House-rule variations: Some groups score crib flushes or muggins differently; toggle these settings as needed.
• Ambiguous pegging inputs: Illegal sequences (totals over 31 without a reset) are rejected to prevent invalid results.
• Strategy guidance: The tool explains scoring but does not guarantee optimal discard or pegging choices.
• Simulation variance: Probabilistic outputs converge with more trials; small samples can show noise.

For best accuracy, double-check card entries and rules before you calculate. When exploring strategy, use multiple simulations and compare expected values across discard or play options.

Units and Symbols

Cribbage does not use physical units, but consistent symbols help interpret calculations. The table below lists shorthand you may see in the Calculator, including point notation and combinatorial symbols used for derivations.

Read the breakdown as a sum of labeled parts. For example, “15×3 = 6 pts; Pairs: 2 = 2 pts; R3×2 = 6 pts; Nobs = 1 pt” means three fifteens, one pair, two runs of three, and nobs. EV appears when you simulate an unknown cut or hidden opponent cards.

Common Issues & Fixes

Most scoring errors come from overlooking multiplicity, misreading flush rules, or entering invalid pegging sequences. A few quick checks prevent almost all mistakes.

• Overlapping runs: Count each distinct run with multiplicity; do not double-count the same subset twice.
• Crib flush: In the crib, all five cards must match suit to score; four-card flushes do not score.
• His nobs: It is the jack in hand matching the cut suit, not “his heels” (cut jack), which is a starter bonus not part of hand counting.
• Pegging totals: Stop at 31; reset the count to 0 after a “go.”
• Duplicate card entries: Ensure each card is unique and valid.

If your result seems off, review the step-by-step lines and match them to the formulas. Correct inputs or rules, then recalculate for a clean, auditable score.

FAQ about Cribbage Calculator

Does the Calculator handle both hand and pegging scores?

Yes. It can score a five-card set (hand or crib) and also evaluate pegging sequences, awarding 15, 31, pairs, multiples, runs, “go,” and last card.

Can I simulate the cut card or unknown opponent cards?

In Simulation mode, you can leave the cut unknown or restrict the deck. The Calculator then estimates probabilities and expected value for your hand or crib.

How does the tool count overlapping runs and multiple pairs?

It uses multiplicity: runs are multiplied by the product of duplicate counts across the span; pairs score via 2 × C(k,2) for each rank present.

Does it support house rules like muggins and crib flush differences?

Yes. Enable muggins to flag missed points, and set crib flush enforcement. You can adjust other options to match your group’s rules.

Cribbage Terms & Definitions

Crib

A separate hand formed from players’ discards, scored by the dealer after both hands are counted.

Cut card

The card revealed after discard that completes each hand for counting; also called the starter.

Dealer

The player who receives the crib and counts last; the advantage alternates between players each round.

Pegging

The alternation of playing cards toward a running total of 31, scoring for 15, 31, pairs, and runs.

Go

A declaration when a player cannot play without exceeding 31; the opponent continues and may score last card or 31.

His nobs

One point for a jack in hand that matches the suit of the cut card.

Run

A sequence of three or more consecutive ranks; duplicates can create multiple runs in one hand or during pegging.

Double run

A run where one rank is duplicated, creating two distinct runs of the same length and additional pair points.

Sources & Further Reading

Here’s a concise overview before we dive into the key points:

• American Cribbage Congress: Official Rules
• Pagat: Cribbage Rules, Variations, and Strategy Notes
• Bicycle Cards: How to Play Cribbage
• Wikipedia: Cribbage — History, Rules, and Scoring
• Cribbage Corner: Rules and Scoring Examples

These points provide quick orientation—use them alongside the full explanations in this page.