Poker bankroll calculator
How many buy-ins you need comes down to three things: your edge, how widely your results swing, and how much risk of going broke you are willing to carry. Pick your format, enter your edge, and get the bankroll that matches.
ROI per tournament in %, or win rate in bb/100 for cash games.
Per tournament, or a full 100-big-blind buy-in for cash games.
Leave empty for the format’s typical value. In bb/100 for cash games, in buy-ins per tournament otherwise.
To see the risk you are running now.
- Buy-ins needed
- 160
- Bankroll needed
- 8,000
- Standard deviation used
- 4 buy-ins
For a 5.0% chance of going broke.
buy-ins = ln(1 / risk) x stdDev² / (2 x edge)
Assumes constant stakes, unlimited play and normally distributed results. Tournament results are right-skewed, so treat the counts as an order of magnitude — and the edge you enter is an estimate too.
How many buy-ins do you need?
Rules of thumb — 20 buy-ins for cash, 100 for tournaments — are a starting point, but they hide the two numbers that decide the answer. A bigger edge needs fewer buy-ins; a wilder game needs many more. The calculator puts both into the standard risk of ruin formula and solves it for the bankroll.
| Format | Edge | 5% risk | 1% risk |
|---|---|---|---|
| Cash game | 2 bb/100 | 61 | 94 |
| Cash game | 5 bb/100 | 25 | 38 |
| Cash game | 10 bb/100 | 13 | 19 |
| Sit & go, 9 players | 3% ROI | 145 | 222 |
| Sit & go, 9 players | 6% ROI | 73 | 111 |
| Sit & go, 9 players | 10% ROI | 44 | 67 |
| Tournaments, 100-200 players | 10% ROI | 240 | 369 |
| Tournaments, 100-200 players | 20% ROI | 120 | 185 |
| Tournaments, 100-200 players | 40% ROI | 60 | 93 |
| Tournaments, 1,000+ players | 10% ROI | 734 | 1,129 |
| Tournaments, 1,000+ players | 20% ROI | 367 | 565 |
| Tournaments, 1,000+ players | 40% ROI | 184 | 283 |
- Inputs
- FormatTournaments, 100-200 players
- Your edge15
- Buy-in50
- Acceptable risk of going broke5%
- Standard deviation (optional)Typical for the format
- Your bankroll (optional)—
- Result
- Buy-ins needed160
- Bankroll needed8,000
- Standard deviation used4 buy-ins
Cash games: buy-ins by win rate
In a cash game the edge is your win rate, measured in big blinds per 100 hands, and a buy-in is 100 big blinds. The bankroll you need falls in proportion to the win rate: at 2 bb/100, a 5% risk takes 61 buy-ins; at 10 bb/100, 13. Small edges are why grinders at tough stakes keep large bankrolls.
The win rate to enter is the one after rake. If you receive rakeback, it lowers your risk too — but only count it if it is reliable.
Tournaments and sit & gos: why field size matters
Bigger fields pay a few players a lot and most players nothing, so results swing much further around the same ROI. The bankroll grows with the square of that spread. At 15% ROI, a 5% risk takes about 29 buy-ins in 9-player sit & gos and about 490 in fields of 1,000 or more.
That gap is the most common bankroll mistake in tournament poker: a sit & go rule of thumb applied to large-field tournaments. If you mix formats, size the bankroll for the wildest one you play regularly.
Where the default standard deviations come from
| Format | Default | Usual range |
|---|---|---|
| Cash game | 90 bb/100 | 80 – 100 bb/100 |
| Sit & go, 9 players | 1.7 buy-ins | 1.5 – 2 buy-ins |
| Tournaments, 100-200 players | 4 buy-ins | 3.5 – 4.5 buy-ins |
| Tournaments, 1,000+ players | 7 buy-ins | 5.5 – 7.5 and up |
Move-down rules: turning the number into a plan
A bankroll figure is most useful as a pair of lines decided before a downswing starts. For 100-200 player tournaments at 15% ROI, 160 buy-ins hold the risk at 5% and 123 hold it at 10%. One workable plan: play the stake while you have 160 buy-ins, and move down if you drop below 123.
- Set the lines in buy-ins, not in money, so they move with the stake.
- Move up only when you hold the buy-ins the next stake needs — not after one good week.
- Moving down after losses lowers your real risk of ruin below what the formula shows, because the formula assumes you never change stakes.
Your edge is an estimate
Every figure here depends on an edge you can only estimate. A few hundred tournaments, or 50,000 hands, still leave a wide range around your observed result — the hourly rate calculator shows how wide. When in doubt, size the bankroll for a smaller edge than you think you have.
The better your records, the better the estimate. Tracking your sessions gives you a running ROI and win rate to enter here instead of a guess.
Bankroll calculator vs risk of ruin calculator
They solve the same formula from opposite ends. This page starts from the risk you accept and gives the bankroll; the risk of ruin calculator starts from the bankroll you have and gives the risk. Enter your current bankroll above and you get both at once.
This number covers one spot. PokeAI covers your game.
The calculator answers how much. PokeAI answers why — on the hands you actually played, using this same engine for every number it gives you.
Questions about this calculator
- How many buy-ins do I need for cash games?
- It depends on your win rate. With a typical spread of 90 bb/100, a 5% risk of going broke takes about 25 buy-ins at 5 bb/100 and about 61 at 2 bb/100.
- How many buy-ins do I need for MTTs?
- Far more than for cash. At 20% ROI, a 5% risk takes about 120 buy-ins in fields of 100-200 players and about 367 in fields of 1,000 or more.
- How many buy-ins do I need for sit & gos?
- Nine-player sit & gos swing much less. At 6% ROI, about 73 buy-ins hold the risk at 5%.
- What risk of going broke should I accept?
- It depends on whether you could rebuild the bankroll. Players who can top up from income often accept 5-10%; players who live on their bankroll usually aim for 1% or less. Halving the risk costs fewer extra buy-ins than people expect.
- What if my win rate or ROI is negative?
- Then no bankroll is enough: given enough time, a losing player goes broke at any stake. The fix is the edge, not the bankroll.
- Should the edge include rake and rakeback?
- Enter your edge after rake. Rakeback and rewards improve it, but only count them if they are reliable. Living expenses drawn from the bankroll are not in the formula — take them out of the bankroll before you enter it.
Related calculators
- Risk of Ruin Calculator
How likely is your bankroll to bust at your ROI and variance, and how many buy-ins you need to bring that risk under 5% or 1%.
- Poker Hourly Rate Calculator
Turn bb/100 into an hourly rate across tables and stakes, add rakeback, and see the range your true win rate could sit in after the hands you have played.
- ICM Calculator
Convert tournament stacks into prize money with the Malmuth-Harville ICM model, and compare an ICM chop with a chip chop before agreeing a deal.