Poker risk of ruin calculator

What does this result mean?

A poker risk of ruin calculator estimates the probability that your bankroll reaches zero before a positive long-run edge has enough time to show. It combines win rate, standard deviation and bankroll depth in buy-ins. More buy-ins, a stronger edge or lower volatility reduces the estimate; a thinner edge or larger swings raises it quickly. The number is a modelled long-run risk, not the chance of losing the next session and not a guarantee that a chosen bankroll is safe. Use a conservative win rate, especially when the sample is small, and a standard deviation that matches the format and stake. If the output is higher than you can genuinely tolerate, reduce the stake or add buy-ins before playing it regularly. A negative or zero edge cannot be protected by bankroll sizing alone, because more money only delays the underlying problem.

How to use the answer responsibly

Treat the calculator as a planning tool, not a verdict on one session. A live poker input is usually an estimate: your win rate is noisy, your standard deviation changes by game type, and your future volume rarely matches the clean number you type into a form. The useful habit is to save the assumptions beside the result so you know what would need to change before the decision changes.

If the result pushes against what you wanted to do, do not smooth the inputs until the answer feels nicer. Make the conservative version first, using a lower win rate, a higher swing rate or fewer weekly hours. Then run the optimistic version. The space between those answers is the real decision area: where a shot needs a stop rule, where a move up needs more buy-ins, or where a good-looking hourly still needs a bigger sample.

Overshove calculators become more useful when the inputs come from your own logged sessions. Rake, tips, travel, hours, stake mix and session length all change the number. A generic benchmark can teach the shape of the problem, but a clean personal log gives the number you should actually act on.