The four craps tools, plus a free table
Every tool here does one job. The Strategy Lab tests betting systems over thousands of shooters. The odds calculator prices any bet and answers dice probability questions. The payout trainer drills the math dealers do in their heads. The roll log records real rolls and tests them for fairness. Beside them sits the full free craps practice table.
| Tool | What it answers | Stores anything? |
|---|---|---|
| Strategy Lab | What does this system do over 10,000 sessions? | No |
| Odds calculator | What does this bet pay, and what are the odds? | No |
| Payout trainer | Can I pay this bet correctly and fast? | Streak and best score, on your device |
| Roll log | Do these rolls look like fair dice? | Your rolls, on your device |
| Free craps table | How does the game feel, roll by roll? | No |
None of them need an account, and none of them ask for anything. That matters for tools like these. A dice probability calculator has no reason to know your email address, and a trainer that works offline in your browser is faster than one that has to talk to a server after each answer you type in.
One engine behind all the craps tools
All five share a single math engine. It is the same code that produces every house edge, payout and probability quoted on this site, including the bet guides and the tables in our open math section. A Place 6 is 1.52% in the calculator, 1.52% in the simulator and 1.52% on the page about place bets.
That consistency is less common than it sounds. Plenty of craps calculators online use rounded house edges from different sources, so a figure on one page disagrees with another. Here, if two numbers ever differ, it is because the rules differ: a field that pays triple on the 12, or buy commission charged up front instead of on a win.
The engine also runs the dice. Every simulated or practice roll comes from your browser’s cryptographic random number generator, each die drawn separately. That keeps the 36 combinations equally likely, which is the only assumption the whole of craps math rests on. It is also why a craps table simulator on this site behaves like real dice.
The Strategy Lab: a craps strategy simulator
The Strategy Lab is our craps simulator. Pick one of eight strategies, from Pass Line with 3-4-5x odds to the Iron Cross and a Martingale on the Pass Line, then set a unit, a bankroll and a number of sessions. It plays every roll and draws a histogram of how all those sessions ended.
The numbers under the chart are the useful part: the share of sessions that finished ahead, the share that went broke, the average result, the total wagered and the theoretical cost. That last figure is the house edge applied to everything you bet. Over enough sessions the average result lands near it, which is exactly what the edge predicts.
Every run carries a shareable link with its random seed built in. Send it to a friend who swears by the 3-Point Molly and they see the same shooters, the same rolls and the same result. It settles an argument faster than a debate at the rail, and costs nothing.
The odds calculator: dice probability and craps payouts
The odds calculator has two halves. The first is a craps payout calculator: choose a bet and the table rules, enter a stake, and it returns the payout, the true odds, the house edge and the cost per roll. The second is a dice odds calculator for questions about totals, rather than bets.
Ask it the chance of rolling a 6 before a 7 and it answers 45.45%. Ask it the chance of seeing at least one 12 in 36 rolls and it works that out too. These are the questions players argue about at the table, usually with the wrong figure, and the dice probability calculator settles them with the exact fraction.
For anyone who wants to learn the arithmetic rather than look it up, our guide to craps payouts walks through each ratio and the rounding casinos use. The calculator is the quick check, the guide explains why the numbers come out the way they do, and between them you should never need to guess.
The payout trainer: practice like a dealer
The payout trainer deals you random situations a dealer faces: a $12 place bet on the 8 that just rolled, $15 in odds on a made 5, a hard 10 hitting for $5. You type the payout and it tells you at once whether you got it right. Difficulty levels move from single bets toward busier layouts.
It keeps a streak and your best score, stored only in your own browser. Players use it to catch short payouts. Dealers in training use it for speed. Both groups find the same thing within a few rounds: the payouts that trip people up are the odds on a 5 or 9 and the buy bets.
The roll log: a dice roll tracker with a fairness test
The roll log is for real rolls, at a casino, on a bubble craps machine or at a kitchen table. Tap each total as it lands, or enter both dice, and the log charts your results against the 36-way expectation. It also tracks your sevens-to-rolls ratio, the number dice-control players watch most closely.
Once you have enough rolls it runs a chi-square test and gives a plain-English verdict on whether the numbers look like fair dice. A few dozen rolls prove nothing, and the tool says so. If you are curious about the claims behind dice control, this is the honest way to test your own throw. Export it as CSV any time.
Which of the craps tools to open first
New to the game? Start at the free table and play a hundred rolls of Pass Line with odds. Then open the payout trainer for ten minutes, because knowing what a bet should pay is the skill that protects you at a real table. Those two steps cover what most players need before their first buy-in.
If you already play and have a favorite system, go straight to the Strategy Lab and run it for 10,000 sessions at your usual unit. Read the share of sessions that went broke before anything else. Then compare the theoretical cost with a plain Pass Line and odds run at the same unit. Which one would you rather pay for?