Poker bankroll calculator

How to work out a bankroll

Bankroll management is one of the central skills in poker. Even a winning player goes broke if his bankroll cannot survive the downswings that are certain to come — the stretches of bad luck where the bankroll only melts away.

The risk-of-ruin formula

The calculator works out the minimum bankroll from the risk-of-ruin formula:

Bankroll = (SD² ÷ (2 × WR)) × ln(1 ÷ RoR)

Here SD is the standard deviation, WR the win rate and RoR the risk of ruin you accept, as a fraction (5% = 0.05). For cash, SD and WR are given in bb/100, so the result comes out in big blinds and is converted into 100bb buy-ins. For tournaments, ROI and deviation are given as percentages per tournament and the same formula answers directly in buy-ins: the bb/100 model does not describe tournament variance, where the prizes are weighted towards the top.

What moves the answer

• Win rate: The profit you expect over 100 hands. The higher the win rate, the smaller the bankroll you need.
• Standard deviation: A measure of variance. The wider your results spread (PLO, tournaments), the deeper the bankroll has to be. Typical cash values are 60–100 bb/100.
• Rakeback: The rake rebate comes on top of what your tracker shows: the win rate there is already net of rake. So rakeback lifts your effective win rate and lowers the bankroll you need.
• Risk of ruin: The chance of losing the whole bankroll. Professionals treat 1–5% as normal.

Tournaments and cash

Variance in tournaments runs far higher than in cash: the prizes are weighted towards the top and every tournament is all-or-nothing. So a tournament player needs a noticeably bigger bankroll: usually 100–500 buy-ins against 25–60 in cash.

How many buy-ins each format needs

Different games carry different variance, so they need different bankrolls. Below are the professional guidelines in common use. The calculator above lets you replace them with your own win rate and deviation.

• Multi-table tournaments: 100–250 buy-ins for MTTs up to 1,000 players, and more for the large high-variance fields. The prizes sit at the top, so the stretches without a cash can run long.
• Sit & Go and Spin & Go: 50–100 buy-ins for ordinary SNGs. Hyper-turbos and lottery-style Spin & Go need the upper end of that range or more, because of the jackpot variance.
• No-limit hold'em, cash: 25–40 buy-ins to take a shot at a stake, and 40–60 to play it comfortably. The standard deviation runs about 80–100 bb/100.
• Pot-limit Omaha, cash: 50–100 buy-ins. The swings in PLO are considerably bigger than in hold'em: hand equities run close together and big pots go in preflop, so the same win rate demands a deeper bankroll.

Shot-taking: how to try a higher stake

Once your bankroll is big enough for the next stake and you still have a cushion, you can take a shot — move up for a while and see whether you are ready to play there. Before the shot begins, decide how many buy-ins you are willing to put into the attempt. While the bankroll stays above the minimum the new stake requires, you can keep playing. The moment it drops below that line, go straight back down. The classic mistake is to keep playing above your stake after hitting your stop-loss, hoping to win it back. That is how even a strong, profitable player loses everything he plays with.