Poker tournament variance & bankroll calculator

Variance is the luck-driven spread of your results around your true skill. In a tournament with hundreds of players only a few percent of the entrants win big prizes, so even a winning player goes through long stretches without a cash. This calculator simulates thousands of random careers to show how wide that spread is for your buy-in, ROI and field size.

It depends on your ROI, the field size and how much risk of ruin you accept. The tool answers it for your own numbers: the “Bankroll for 5% risk of ruin” card is the size at which only 1 in 20 simulated careers loses the whole bankroll over the period you chose. With the default settings (500 players, 10% ROI, 900 tournaments) that is about 175 buy-ins, and a 100 buy-in bankroll is lost in roughly one career out of five.

Much less than most players think. With the default field of 500 the standard deviation is about 4.7 buy-ins per tournament, so after 1,000 tournaments a measured ROI of 10% is consistent with a true ROI anywhere from about −19% to +39%. The “How sure are you about your ROI?” card shows this for your numbers.

Each simulated tournament has your field size, pays the top 15% with a steep payout ladder and takes 8% rake. Your skill tilts the finishing position so that the average return equals the ROI you enter. The calculator then plays your tournaments thousands of times with random finishes and reports the spread. It is a model, not a promise.

No. It models a freezeout with a standard payout ladder. Progressive knockout (PKO) and rebuy events have different variance, so treat the result as a guide for plain freezeouts.

No. The simulation runs in your browser. The link button only stores your inputs in the address of this page.