Tools

Bankroll Calculator

The bankroll a given winrate actually requires to keep your risk of going broke below a line you choose.

Buy-ins you need
Bankroll in big blinds

Required bankroll = variance × ln(1 ÷ risk of ruin) ÷ (2 × winrate). A lower winrate or a stricter risk tolerance demands a deeper roll — fast. With a non-winning winrate, no bankroll is safe.

Frequently asked

How many buy-ins do I need for poker?
It depends on your winrate and variance, not a fixed number. Enter both plus the risk of ruin you will accept and the tool returns the exact bankroll, in big blinds and buy-ins.
How is the required bankroll calculated?
Required bankroll = variance × ln(1 ÷ risk of ruin) ÷ (2 × winrate). A smaller edge or a stricter risk tolerance demands a much deeper roll.
What if I am a break-even player?
No bankroll is safe with a non-winning winrate — risk of ruin approaches certainty over a long enough sample.
Is this bankroll calculator free?
Yes. It runs in your browser, needs no signup, and the result is an exact formula.