Crash Game Math Explained: Odds of Every Cash-Out Multiplier

18+ only. Contains affiliate links — we may earn a commission. Not for residents of the US, UK, France, Germany, Netherlands, Spain, Austria, Australia, Ontario or Vietnam. Not legal or financial advice.

In Crash a multiplier climbs from 1.00× until it “crashes”. You cash out before the crash to win stake × multiplier; if you’re still in when it crashes, you lose the stake. All players share the same round result. 18+ only.

How Crash results are generated

Crash games usually use a hash chain rather than per-player seeds. The operator generates a long chain where each game hash is the SHA-256 of the next one, publishes the final hash and a salt in advance (bustabit announces these “seeding events” on Bitcointalk), and plays the chain backwards. Stake also points to a salted hash model for its Crash game (Stake game events).

bustabit’s open-source verifier (github.com/bustabit/verifier) computes each round as:

1. h = HMAC_SHA256(key = salt, message = game hash)
2. X = (first 52 bits of h) / 2⁵² (uniform in [0, 1))
3. result = max(1, floor(99 / (1 − X)) / 100)

The 99 instead of 100 is a 1% house edge.

Probability of reaching each multiplier

From step 3, P(result ≥ m) = 0.99 / m:

About 1.98% of rounds bust at 1.00× (when 99/(1−X) < 101, i.e. X < 2/101). These numbers are for bustabit’s formula; other operators can use different edges or rules, so read their fairness page.

How to verify a crash round

• Chain check: SHA-256(game hash) must equal the previous round’s hash. That proves the round was fixed when the chain was created.
• Result check: recompute the multiplier with the salt and the formula above.

Our provably fair verifier has a Crash mode (labelled example → 1.44×). Background: provably fair explained.

Why auto-cashout systems lose

A fixed auto-cashout at m has expected value m × 0.99/m − 1 = −1%. Raising the bet after a loss (Martingale at 2×) needs a 49.5%-win streak to keep going; 8 losses in a row (≈ 0.42% from any given start) multiplies your stake 256×. Sum of negative-EV bets = negative EV. Simulate it with the risk of ruin simulator.

To compare Crash with a finite-board game, change the mine count in the Mines odds calculator; the Dice table with an assumed 1% edge provides a second comparison of payout versus hit rate.

The Martingale bust calculator measures a fixed losing-streak threshold, while the payout and RTP audit checks expected return from a complete discrete outcome table. Neither predicts the next crash.

Key takeaways

• Chance to reach m = 0.99 / m on bustabit’s formula.
• Hash chains prove rounds weren’t changed, not that you’ll win.
• Decide stop-loss and session time before you start. Responsible gambling.

Related: Limbo odds · Dice odds · Mines odds · Plinko odds

For a multi-outcome contrast to a fixed Crash target, the Plinko odds calculator shows how rows determine slot probabilities while the complete multiplier array determines expected return.

Crash’s reach-target model differs from a numbered-ball draw. The Keno odds calculator shows every possible hit count, including impossible counts at zero probability.

Change the target, stake and assumed edge in the Crash cashout calculator to compare win frequency with EV and expected loss over a fixed bet count. Its default 1% edge is an example.

For the same-edge comparison across mechanics and variance, read Crash vs Limbo vs Dice; matching EV does not mean matching payout rules.

Ready to try Mint.io?

Before considering Mint.io, compare the game's rules with this Crash model and set a loss and session limit. Read our full Mint.io review, set a budget, and play responsibly.

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