Betting & Risk Calculator
This calculator shows what your spread earns per hour, how large the swings are, and the probability your bankroll runs out before the long run arrives. Betting software sells these numbers. Ours are free, computed from 20,000,000 simulated hands per rule configuration. Pick your table's rules below and the numbers are that table's.
Table rules
Every combination is its own 20-million-hand simulation; 6:5 is derived exactly from the measured natural-win rate. Fixed: max 4 split hands (the 2-vs-4 difference is below measurement precision) and the US peek game — ENHC and double-restriction rules aren't modeled yet.
Bet spread (units)
Taking this spread on the road? Plan a trip with it → Your table setup carries over.
| True count | How often | Edge | Your bet | EV/hr from this count |
|---|---|---|---|---|
| -10 and below | 0.1% | -6.34% | 1u ($25) | −$0.15 |
| -9 | 0.1% | -6.54% | 1u ($25) | −$0.16 |
| -8 | 0.2% | -5.76% | 1u ($25) | −$0.29 |
| -7 | 0.4% | -4.87% | 1u ($25) | −$0.45 |
| -6 | 0.7% | -4.10% | 1u ($25) | −$0.69 |
| -5 | 1.2% | -3.35% | 1u ($25) | −$1.03 |
| -4 | 2.2% | -2.98% | 1u ($25) | −$1.61 |
| -3 | 3.8% | -2.55% | 1u ($25) | −$2.42 |
| -2 | 6.7% | -1.88% | 1u ($25) | −$3.17 |
| -1 | 12.3% | -1.29% | 1u ($25) | −$3.99 |
| +0 | 45.5% | -0.46% | 1u ($25) | −$5.21 |
| +1 | 11.8% | 0.36% | 1u ($25) | $1.06 |
| +2 | 6.5% | 1.02% | 2u ($50) | $3.33 |
| +3 | 3.7% | 1.63% | 4u ($100) | $6.03 |
| +4 | 2.1% | 2.34% | 6u ($150) | $7.38 |
| +5 | 1.2% | 2.61% | 8u ($200) | $6.20 |
| +6 | 0.6% | 3.74% | 8u ($200) | $4.84 |
| +7 | 0.4% | 4.24% | 8u ($200) | $3.00 |
| +8 | 0.2% | 5.44% | 8u ($200) | $2.09 |
| +9 | 0.1% | 6.21% | 8u ($200) | $1.20 |
| +10 | 0.0% | 5.60% | 8u ($200) | $0.53 |
| +11 | 0.0% | 6.57% | 8u ($200) | $0.30 |
| +12 and up | 0.0% | 8.77% | 8u ($200) | $0.33 |
How to read these numbers
EV per hour is your long-run average, the number that pays you. Standard deviation per hour is the number that tests you. A typical hour lands anywhere within a swing many times your EV, which is why the hourly range matters more than the average for your nerves and your bankroll. Risk of ruin is the probability of losing the entire bankroll before your edge shows up. Serious counters keep it under 10%, conservative ones under 5%. N0 is the number of hands until your expected win outruns one standard deviation, a fair estimate of how long you must play before results start meaning anything.
The two levers that matter
If your risk of ruin is too high, you have two options: shrink your unit relative to your bankroll, or flatten your spread. Chasing a bigger hourly EV with bets your bankroll can't carry doesn't raise your winnings. It raises the probability that you won't be around to collect them. The counting course's bankroll lesson covers the reasoning; this page does the arithmetic for your exact numbers. The “generate optimal spread” button searches Kelly-shaped spreads for the highest EV that keeps your risk of ruin under 5%, and tells you when no spread can, which means your unit is too big for your bankroll.
Methodology
Per-count performance measured over 20,000,000 rounds per rule configuration (decks × S17/H17 × penetration × DAS × surrender × RSA; max 4 split hands · US peek game · measured at 3:2 (6:5 derived from natural-win rate) · hi-lo Index Plays with live counts on the dev arm), playing perfect total-dependent basic strategy with a flat bet, bucketed by the Hi-Lo true count at the moment of each deal (truncated toward zero, half-deck estimation). EV scales linearly with your bet and variance with its square, which is what lets one simulation price any spread. With the deviations toggle on, the simulated player plays the Illustrious 18 + Fab 4 with live in-hand counts and takes insurance at true +3, the numbers a trained counter earns. Toggled off, the player uses pure basic strategy, the conservative floor. Risk of ruin uses the standard diffusion approximation exp(−2·EV·B/Var). Generated 2026-08-08 with a deterministic seed; rerunning reproduces every number.
Practice the skills these numbers assume on the training table, and remember the bankroll rule: this math only protects money you could afford to lose entirely.