CRA 321: How to Use a Craps Session Loss Calculator

A craps session loss calculator is useful only when the inputs describe the bets that actually reach the layout. Entering “$10 Pass Line” while also taking odds, placing numbers, betting the Field, and making center bets produces a comforting answer to the wrong question.

The reliable method is to separate the session into wager groups, calculate the theoretical loss for each group, and add the results.

The calculation to use for each wager

For a single bet type:

Expected loss = Stake × Number of resolved decisions × House edge

For several bet types:

Total expected loss = Σ(Stakeᵢ × Decisionsᵢ × Edgeᵢ)

Where:

• Stakeᵢ is the average amount on wager type i;
• Decisionsᵢ is the number of times that wager resolves;
• Edgeᵢ is that wager’s house edge written as a decimal;
• Σ means add the expected loss from every wager group.

The output is theoretical loss: the probability-weighted average cost of repeating that betting pattern. It is not a forecast of the amount that will be lost tonight.

Why one average bet is often misleading in craps

Craps wagers operate on different clocks.

• A Field wager resolves on the next roll.
• Any Seven and most proposition wagers resolve on one roll.
• A Pass Line decision may finish on the come-out roll or continue through several rolls until the point or 7 appears.
• A Place 6 left working resolves when 6 wins or 7 loses; unrelated totals do not settle it.
• An odds bet exists only after a point is established and resolves with the associated line bet.

Multiplying every chip on the layout by the number of rolls therefore overstates some wagers and correctly counts others. The calculator needs wager decisions or resolved action, not just table rolls.

Step 1: Write down the real betting pattern

Do not start with the table minimum. Start with a normal sequence.

A player might describe the session as “$10 craps,” but the recurring layout could be:

• $10 Pass Line;
• $20 odds when a point is established;
• $12 Place 6 kept working;
• $5 Field on selected rolls;
• $5 Any Seven after an unusually long roll.

The Pass Line is only the base. The other wagers change total action, expected loss, and bankroll swing.

If bet sizes vary, use a realistic average for each category. Do not use the largest bet ever made, and do not use the smallest opening bet if later action is consistently larger.

Step 2: Use the correct edge for each wager

Craps does not have one universal house edge. Each wager has its own probability and payout.

Common reference values under standard rules include:

Rules vary. A Field bet paying only 2:1 on both 2 and 12 has a higher edge than the version in the table. Buy-bet commission timing can also change the effective cost. Use the rules posted or approved for the table being modeled.

The Craps House Edge page compares more wagers, while Craps Odds explains the dice combinations behind the figures.

Step 3: Count decisions by bet type

A session estimate can be built from observation, a planned number of bets, or time and pace. Whichever method is used, count each wager according to when it resolves.

Pass Line and Don’t Pass

Count completed line-bet cycles. A come-out natural or craps result completes a decision immediately. If a point is established, the decision completes when the point repeats or 7 appears.

Do not count every intermediate roll as a new line bet unless the player actually places additional Come or Don’t Come wagers.

Odds

Count the number of line decisions in which odds were taken. The stake may vary by point or bankroll, so use the average odds amount actually placed.

Odds have zero house edge because they pay true odds, but they must still be included in the session model. They add no theoretical loss at correct payouts, yet they increase total money at risk and short-term variance.

Place and buy bets

If a Place 6 remains up after a win, each completed 6-versus-7 cycle is a new resolved decision. Rolls of 2, 3, 4, 5, 8, 9, 10, 11, or 12 do not by themselves settle that Place 6.

If the bet is taken down, pressed, reduced, or switched off, the average stake and number of active decisions should reflect those changes.

One-roll wagers

A Field, Any Seven, Any Craps, or single-roll proposition bet resolves on the next roll. If the player makes the bet 25 times, the calculator should count 25 decisions even if the entire table session contains many more rolls.

This is why small proposition wagers can matter: they may be placed frequently and often carry a much higher edge than the line bet.

Step 4: Calculate each row, then add them

Consider this illustrative session record:

The calculations are:

• Pass Line: $10 × 30 × 0.01414 = $4.24
• Odds: $20 × 20 × 0 = $0.00
• Place 6: $12 × 40 × 0.01515 = $7.27
• Field: $5 × 60 × 0.02778 = $8.33
• Any Seven: $5 × 10 × 0.16667 = $8.33

The player put only $50 of total action through Any Seven, yet that small category creates almost the same theoretical loss as $300 of Field action. The reason is the much larger edge.

The zero-edge odds wagers account for more than a quarter of all action in the example but none of the $28.18 theoretical loss. They still create substantial bankroll swings because a fair wager can lose in the short term.

Step 5: Calculate a weighted edge only if it helps

A blended or weighted house edge can summarize the full betting pattern:

Weighted edge = Total expected loss ÷ Total resolved action

For the example:

$28.18 ÷ $1,530 = 1.842%

This number is useful for comparing two complete patterns, but it hides the reason for the result. A player could reduce the weighted edge simply by adding more zero-edge odds action while also increasing volatility. The row-by-row view is therefore more informative than the blended percentage alone.

How to enter the pattern into the site tools

The Expected Loss Calculator accepts an average bet, number of bets or session pace, and house edge. For a simple Pass-Line-only plan, one calculation may be enough.

For mixed craps action, use one of these approaches:

1. Run each wager category separately and add the expected-loss outputs.
2. Calculate total action and weighted edge from a table like the example, then enter those blended figures.
3. Use a spreadsheet when stakes, frequencies, presses, or commission rules vary substantially.

The first approach is the easiest to audit. It also exposes expensive one-roll bets that disappear inside a blended average.

Use the Craps Odds Calculator for payout and true-odds checks. Use the House Edge Calculator only when the outcome probabilities and net payouts are known accurately.

The official rules matter

The current Washington State Gambling Commission craps game description illustrates how approved wagers, procedures, and payout rules are formally specified. A calculator cannot correct a rule assumption that does not match the actual table.

Before entering a Field, buy, lay, or promotional wager, verify:

• the displayed payout;
• whether commission is paid on the amount bet or amount won;
• whether commission is collected before or after a win;
• which totals push;
• whether a place or buy bet is working on the come-out roll;
• whether the wager remains up after winning.

These details can change both the edge and the number of resolved decisions.

Mistakes that produce false precision

Using the buy-in as total action. Chips can be wagered repeatedly. A $300 buy-in may generate far more than $300 of resolved wagers.

Applying the Pass Line edge to the whole layout. Place, Field, hardway, and proposition wagers do not inherit the Pass Line price.

Charging house edge to odds. Correctly paid odds have 0% house edge. Their risk is variance, not theoretical disadvantage.

Counting every roll for every wager. Only one-roll wagers necessarily resolve every roll.

Ignoring presses and regressions. A Place 6 that moves from $12 to $18 to $30 does not have a $12 average stake.

Treating the output as a stop-loss. An expected loss of $28.18 does not mean the session will stop near that amount. Actual results can be much better or worse.

Reporting cents from rough inputs. If pace and bet frequency are estimates, an answer such as “about $28” is more honest than pretending $28.18 is a personal forecast.

What the result should change

The calculator is most useful before play. It can show that:

• a modest base bet becomes expensive after repeated side action;
• faster one-roll wagers create more hourly exposure;
• taking odds lowers the blended edge but raises bankroll movement;
• reducing time or frequency can matter as much as reducing the posted stake;
• two players at the same $10 table may be creating completely different theoretical costs.

It cannot tell you which shooter will have a long hand, whether the next roll will be 7, or how much the next session will win or lose.

For the time-based version of the calculation, continue to Craps Expected Loss Per Hour. Then read Craps Variance and the Craps Variance Simulator Guide so the average cost is not mistaken for the likely path of one visit.