Betting and casino calculators
Nine calculators, all running in your browser, none of them storing anything or asking who you are. Each one shows the arithmetic it used and says plainly what the result does not mean.
Decimal, fractional, American and implied, plus the margin built into the price.
Combined odds across any number of legs, and how much margin compounds with each one.
What an offer is worth after wagering, contribution weighting and the cap on winnings.
Growth-optimal stake, the edge it depends on, and the fractional version people actually use.
RTP converted into what an hour costs at your stake and your game speed.
Chance of reaching a target before reaching zero, given a bankroll and an edge.
Stake needed to lock a position, and whether two prices constitute an arbitrage.
Turnover a bonus requires and the average cost of clearing it.
Recompute a bet result from its seeds and check it against the published hash.
Why these show their working
A calculator that returns a number without stating its assumptions is a worse tool than no calculator, because it converts a guess into something that looks like a fact. Every tool here states the model it uses, and where a model is a simplification it says so on the page rather than in a disclaimer nobody reads.
Three of them exist mainly to show that an answer is negative. The bonus value calculator usually returns a negative expected value, the risk of ruin calculator returns a certainty given unlimited time, and the Kelly calculator returns no bet for every casino game. Those are not bugs in the tools, they are the arithmetic of the products they describe.
What these tools cannot tell you
None of them predict a session. Every figure is an expectation across many repetitions, and the distance between an expectation and any single evening is enormous, which is precisely why gambling feels winnable while remaining negative in aggregate.
They also say nothing about whether an operator will pay. That is a separate question, and it is the one the rest of this site exists to answer. The register, the contradictions we have documented, and what withdrawal terms actually commit to.