Blackjack 3000

Risk of Ruin Calculator

Use this estimate to align bet size and bankroll. Lower risk of ruin usually requires smaller stakes or more bankroll.

Calculator

Approximation: ROR = e^(-2 * edge * bankroll / variance), where edge is decimal per hand.

Practical Targets

  • Recreational bankroll: often 20%+ ROR is tolerated.
  • Serious counters: many target 5% or lower.
  • If your ROR is high, lower max bet or increase bankroll units.