What is a good poker bankroll?

For online cash games, a common target is 30 to 50 buy-ins (3,000 to 5,000 big blinds). The calculator shows your actual risk of ruin for any bankroll.

What standard deviation should I use?

Use the figure from your tracking software if you have it. Otherwise 80 for full ring, 100 for 6-max No-Limit Hold'em and 140 or more for PLO.

Can a winning player be down after 100,000 hands?

Yes. At 2 bb/100 with an SD of 90, about one in four will be.

What does bb/100 mean?

Big blinds won per 100 hands. It's the standard win-rate measure because it works the same at every stake.

Poker Variance Calculator

Your results

Win rate (bb/100)Big blinds won per 100 hands. Your tracker shows it.

Standard deviation (bb/100)Around 70 to 90 at full ring, 90 to 110 at 6-max, more for heads-up or PLO.

Number of hands

Bankroll (big blinds)

Big blind ($)At $0.25/$0.50 the big blind is $0.50.

What to expect

Expected result (big blinds)–

Expected result in money–

95% range, low end (bb)–

95% range, high end (bb)–

Chance of being down after these hands–

Risk of ruin with your bankroll–

Bankroll for a 5% risk of ruin (bb)–

Bankroll for a 1% risk of ruin (bb)–

Uses the normal approximation: expected result = win rate × hands ÷ 100, swing = SD × √(hands ÷ 100). Risk of ruin = e^(−2 × win rate × bankroll ÷ SD²), with everything per 100 hands. It assumes your true win rate is the one you enter, and few people know theirs that well.

A poker variance calculator shows how wide the road is. A player winning 5 big blinds per 100 hands with a standard deviation of 90 expects to be 2,500 big blinds up after 50,000 hands. But 95% of the time the real result lands anywhere between 1,444 big blinds down and 6,444 up, and there’s a 10.7% chance of being behind after all that work.

That’s at $0.25/$0.50, a $1,250 expected profit with a realistic outcome that could be a loss. Put your own numbers in the free calculator above.

Poker variance calculator: the inputs

Win rate (bb/100): big blinds won per 100 hands. Your tracking software shows it. 3 to 5 is a solid online cash-game rate, 10 is excellent.
Standard deviation (bb/100): how much your results swing. Full ring is usually 70 to 90, 6-max 90 to 110, and PLO or heads-up much more.
Hands: how far ahead you want to look. 50,000 hands is a few months for a regular, a year or more for a casual player.
Bankroll: in big blinds, so 3,000 bb at $0.50 is $1,500.

Risk of ruin

Risk of ruin is the chance your bankroll ever hits zero if you keep playing forever at the same win rate. With 5 bb/100, an SD of 90 and 3,000 big blinds, it’s about 2.5%. Cut the bankroll to 1,500 bb and it rises to about 16%. Halve the win rate instead and it’s back near 16%. The calculator also shows the bankroll you’d need for a 5% and a 1% risk: 2,427 and 3,730 big blinds here.

The formula assumes you know your true win rate. Almost nobody does. Over 50,000 hands with an SD of 90, the win rate your graph shows has a margin of error of about 4 bb/100 either way. Plan with a lower figure than the graph says.

Downswings are normal

Run a 2 bb/100 winner over 100,000 hands and there’s still about a 24% chance of being down. That’s why a bad month says so little. Before you change your game, check how many hands it covers and put that number in the calculator. The pot odds calculator helps with the decisions; this page helps with the nerves.

Variance is real, and so are losing players. Move down in stakes before the bankroll forces you to. BeGambleAware.org is free and confidential if it stops being fun.