Betting & Risk Calculator
This calculator shows what your spread earns per hour, how big a normal hourly swing is, and the probability that 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. To price your own game, pick your counting system, enter your bankroll and your unit, set the table rules to match your casino, and enter your spread. Every number on the page is then for that table.
Table rules
Each rule combination is its own 20-million-hand simulation. The 6:5 numbers are derived exactly from the measured natural-win rate. Every run caps splits at 4 hands, because the difference between 2 and 4 is below measurement precision.
Bet spread (units)
This table setup carries over to the trip planner. Plan a trip with this spread →
| True count | How often | Edge | Your bet | Hourly EV 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. Standard deviation per hour is the size of a normal hourly swing, and it runs many times larger than the EV. Your nerves and your bankroll have to absorb that swing, not the average. Risk of ruin is the probability of losing the entire bankroll before your edge shows up.
Risk of ruin by unit size
A common target is under 10%, while conservative players target under 5%; those are risk limits, not unit-sizing rules. Use this calculator because the result changes with the bankroll, spread, and game assumptions. N0 is the number of hands it takes for your expected win to exceed one standard deviation. Before that many hands, your results tell you nothing about your edge.
Two ways to cut risk
If your risk of ruin is too high, shrink your unit relative to your bankroll, or flatten your spread. Chasing a bigger hourly EV with bets your bankroll cannot carry does not raise your winnings. It raises the probability that you go broke before you collect them. The counting course's bankroll lesson covers the reasoning. This page does the arithmetic for your exact numbers. To find the best spread your bankroll can carry, click Generate optimal spread. It searches Kelly-shaped spreads for the highest EV that keeps your risk of ruin under 5%. If no spread can, it says so, and that means your unit is too big for your bankroll.
Hi-Lo taught bet ramp · max 8 units
Methodology
We measured per-count performance 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). The simulated player plays perfect total-dependent basic strategy with a flat bet, and we bucket each round by the Hi-Lo True Count at the moment of the deal (truncated toward zero, half-deck estimation). EV scales linearly with your bet and variance with its square, so one simulation prices any spread. With Playing deviations checked, the simulated player plays the Illustrious 18 + Fab 4 with live in-hand counts and takes insurance at true +3, which is what a trained counter earns. Unchecked, the player uses basic strategy only, the lower bound. Risk of ruin uses the standard diffusion approximation exp(−2·EV·B/Var). We generated the data 2026-08-08 with a deterministic seed, so a rerun reproduces every number.
Practice the skills these numbers assume on the training table. This math protects only money you can afford to lose entirely.