The most common bankroll question in poker has a short answer and a longer explanation, and you need both. The short answer: cash players want thirty to fifty buy-ins for the stake they play, tournament players want around a hundred, and more for large fields. The longer explanation is why those numbers are what they are, and why live poker pushes them higher. Get this right and a bad run is an inconvenience. Get it wrong and it ends your poker.
The numbers, up front
Those are working numbers, not laws, and the rest of this piece is about how to adjust them for your situation.
Why cash needs fewer buy-ins than tournaments
The gap between thirty and a hundred is not arbitrary. It is variance.
Cash games are relatively low variance. You sit with a full stack, you can leave whenever you want, and your results are measured over a large number of hands per session. A winning cash player still has losing weeks, but the swings are contained, so a roll of thirty to fifty buy-ins is usually enough to ride them out.
Tournaments are the opposite. The money is concentrated at the top, so you can play well for months, cash rarely, and only get paid properly when you go deep in a big field. That structure produces long, brutal downswings that have nothing to do with how well you are playing. A hundred buy-ins is not timidity, it is the depth required for your edge to survive the dry spells that tournament maths guarantees. There is more on this in Poker Variance Explained.
Why live needs more than online
Two forces push the live requirement above the online one.
First, hands per hour. Online you might see sixty to a hundred hands an hour per table, and you can play several tables at once. Live you see maybe thirty. Fewer hands means variance takes far longer to smooth out over the same number of sessions, so you need a deeper cushion to survive the same swing.
Second, cost. Live poker carries expenses online does not: travel, a hotel for a festival, food, sometimes a day off work. A live tournament bankroll that only counts buy-ins is understating the real cost of playing. Budget a festival trip as a whole, and track your expenses per session so your true hourly is honest. Sit at the upper end of every range above if you play mostly live.
Shot-taking and moving down
The numbers are only useful if you also have a rule for what to do when you cross them, in both directions.
Take a shot at the next stake up when your roll clears its buy-in requirement, and set aside a fixed number of buy-ins for the attempt. More importantly, decide in advance to move back down the moment your roll falls below the requirement for your current stake. The move-down rule is the one that protects careers, because it turns the hardest emotional decision in poker into a mechanical one. You are not failing by dropping down. You are keeping the roll that lets you climb again.
You cannot manage what you do not track
All of this assumes you actually know your bankroll and your results, and most players only know them approximately. Log every session in a bankroll tracker, cash and tournament, with expenses, and the buy-in maths stops being a guess. You will see your real win rate by stake, which tells you whether you belong at the level, and your variance, which stops a rough fortnight from panicking you into a bad move. Drill your fundamentals with the Pot Odds Trainer so your edge is real, then protect it with a roll deep enough to let it play out. The full framework is in Poker Bankroll Management.
Work out your number, then track every session so you always know where you stand. Start training free at drills.poker.