Free Blackjack Bankroll & Risk Calculator

What this calculator answers

Four questions, and they are the four that decide whether a counting career survives its own variance. How much bankroll does this game and this spread actually require? What are the odds it dies before the long run arrives? What should I be betting at each true count? And how long before my results mean anything at all?

It runs in the browser, needs no account, saves nothing, and gives everyone the same full-precision answer. There is no reduced version and nothing is withheld for a paid tier.

Comparable desktop software sells for $125 to $250. This does the same arithmetic and costs nothing, which is a policy rather than a promotion — the rule here is to give more than we take.

Risk of ruin — the number most people skip

Risk of ruin is the probability that a bankroll is destroyed before an edge has time to show up. It depends on three things: how big the edge is, how violently the results swing around it, and how much money is standing behind the bets. Change any one and the answer moves sharply, which is why a single remembered figure — 'you need a hundred units' — is worth very little.

The calculator gives the whole family of it. Ruin over an unlimited horizon, which is the strict version. Ruin within a finite trip, which is always kinder, because having less time to go broke can only help. And the two-barrier version: the chance of reaching a profit target before losing the bankroll, which is the honest way to price 'can I run it up?' — it counts both endings instead of only the one you were hoping for.

It also inverts the question, which is usually the useful direction: given the risk you are willing to carry, how much bankroll does this game require? Set five percent, or one, and read the number off.

The bet ramp it works out for you

Bet sizing is where most of the edge is won or thrown away, and it is the part a chart cannot help with, because the right bet depends on your bankroll rather than on the cards. The calculator derives a ramp: the units to put out at each true count, from the measured edge at that count and how much risk you are prepared to run.

It is generated, not looked up. The edge at each true count is measured by playing millions of hands of the game you configured, and the bet at each count follows from that measurement and your bankroll. Change the bankroll and the ramp changes; ask for less risk and it flattens.

It will also tell you when a ramp does not beat the game. That is the most useful thing a bankroll tool can say and the thing most of them will not: at a modest bankroll, disciplined bet sizing on every hand can come out roughly break-even, because the hands played at a negative count drag away what the good counts produce. Seeing that on screen is worth more than a confident number that flatters you.

Planning a trip

Set the days, the hours a day, and the pace, and it returns the expected result and the range that nineteen trips in twenty will land inside. That range is almost always wider than people expect, and it is the point: a losing weekend is not evidence of anything, and neither is a winning one.

Trip risk of ruin is computed separately from the unlimited-horizon figure, because a weekend is not a career and treating them the same overstates the danger.

The cone — seeing variance instead of reading a percentage

A thousand simulated versions of the same stretch of play are drawn as a widening cone of outcomes, with the middle half and the middle ninety percent shaded. The average is a line through it, and nobody plays the average.

A standard deviation is a number people nod at and do not feel. The cone is the same fact in a form that is hard to argue with: even a real edge spends long stretches underwater, and the picture shows how long and how far.

How to check that any of this is true

This is the part that matters more than the features, and it is where the tool is different rather than merely cheaper.

Two independent calculations produce every number, and they are built to disagree if either is wrong. One is closed-form probability — expectation, variance, and the classical ruin formulas — derived in the source rather than asserted. The other plays actual hands: seeded shoes, dealt and played by the same strategy engine as the free drills and the graded test, with the same basic strategy, the same index deviations, and the same insurance rule.

The two are then checked against each other. The simulation measures the edge and the spread of outcomes; the closed form predicts how often ruin should follow; and thousands of independent bankroll paths are run to see how often it actually does. Where they agree you can trust either. Where they disagree the simulation is the more honest one, because it assumed less — and the disagreement is reported rather than smoothed away.

No figure here was imported from anyone else's software, and no reference table was copied from any source. Every number was produced by playing the hands. The methods note on the calculator says all of this on the page, next to the results, where a claim about honesty is cheap and a published cross-check is not.

Why it is free

Because the arithmetic of a game is not a product. Knowing what your bankroll can survive is the difference between playing and gambling, and putting that behind a price mostly stops the people who need it most from finding out.

The course is a separate thing and is paid. This is not a sample of it, and none of the figures above are withheld or blunted to make the paid thing look better.

Questions

Is there a free blackjack simulator that does not need to be bought?

This one. It runs in a browser on any device, requires no account and no download, and gives the same full-precision answers to everyone. Comparable desktop software sells for $125 to $250 as a paid package.

How much bankroll do I need to count cards?

There is no single number, and anyone who gives you one without asking about your spread and your game is guessing. It depends on the edge that game offers, how wide you spread, and how much risk of ruin you are willing to carry. The calculator inverts the question directly: choose an acceptable risk, and it returns the bankroll that produces it.

What is a reasonable risk of ruin to accept?

That is a personal decision rather than a mathematical one, which is why the tool reports several rather than recommending one. What the arithmetic can tell you is the price of each choice: a lower risk demands a larger bankroll or smaller bets, and there is no configuration that removes the risk entirely while any money is on the table.

Is a losing month evidence that I am doing something wrong?

Usually not, and that is the honest and unsatisfying answer. The calculator reports the number of hands before expected profit is as large as the typical swing around it, and for most real games it is far more than a month of ordinary play. Below that, a good run and a bad one look identical from the inside — which is the reason to keep records rather than impressions.

Does it work out the optimal bet spread as well?

Yes, and it derives it rather than reciting one. The edge at each true count is measured by simulation for the rules you set, and the recommended bet at each count follows from that plus your bankroll and your risk tolerance. It also flags when the resulting ramp does not beat the game.

Where do the numbers come from?

From playing hands. A seeded simulation deals and plays millions of rounds with the same strategy engine used by the free drills, and a closed-form calculation checks it independently. Nothing was copied from any published table or any other software, and the cross-check between the two methods is shown on the calculator page.