Martingale Calculator
18+ · Gambling can be addictive. The house edge means you lose over time.
- Bust within 500 rounds
- 88.45%
- Exact, over every possible sequence
- Losing streak that ends it
- 6 in a row
- You survive 5. Losing 6 straight costs $630.00
- Expected result
- -$162.62
- $6,016.99 wagered on average
Each finished streak wins $10.00. A streak of 6 losses, which ends the system from your starting bankroll, has a 1.834% chance (1 in 55) every time you start one. You finish ahead 16.9% of the time. With a 2.70% house edge the expected result is -$162.62: the many small wins don't make up for the rare big loss.
Bust chance by round
| 50 rounds | 125 rounds | 250 rounds | 375 rounds | 500 rounds |
|---|---|---|---|---|
| 35.14% | 55.93% | 75.65% | 84.41% | 88.45% |
20 simulated players
Random runs with your settings: 17 of 20 went bust (red). The exact figure above is what that share tends to over many runs.
The bet ladder
| Bet # | Stake | Lost if all lose | Chance to lose this many in a row |
|---|---|---|---|
| 1 | $10.00 | $10.00 | 51.351% |
| 2 | $20.00 | $30.00 | 26.370% |
| 3 | $40.00 | $70.00 | 13.541% |
| 4 | $80.00 | $150.00 | 6.954% |
| 5 | $160.00 | $310.00 | 3.571% |
| 6 | $320.00 | $630.00 | 1.834% |
| 7 | $640.00 | More than you have | 0.942% |
If this is how you're trying to win back losses, take a break. Our responsible gambling page lists free help.
How to use it
- Enter your bankroll and base bet, and the table limit if there is one.
- Enter the win chance and payout of the bet you'd repeat. 18/37 at 2x is red on a single-zero roulette wheel.
- Set how many rounds you'd play.
- Read the bust chance, the losing streak that ends the system and the expected result. Run the simulation again to see different luck.
- Copy the URL to share your settings.
How the martingale works
Start with a base bet b. After a loss, bet enough that a win gets back everything lost in the streak plus the base profit. At even money (2x) that means doubling. At other payouts the ratio is different, and the calculator handles it:
lost after k losses = b × (r^k - 1) ÷ (r - 1)
profit of every finished streak = b × (d - 1)
The system ends when the next bet is bigger than what you have left or than the table limit. That's what we call bust here: you've just lost a whole streak and can't place the bet that would win it back.
| Bankroll ($10 base) | Bets in a row | Lost if all lose | Chance on red (single zero) |
|---|---|---|---|
| $100 | 3 | $70 | 13.5412% |
| $1,000 | 6 | $630 | 1.8336% |
| $10,000 | 9 | $5,110 | 0.2483% |
| $100,000 | 13 | $81,910 | 0.0173% |
Every tenfold increase in bankroll adds only three or four more bets, because the bets double.
Why the expected result is always negative
Every bet you place has the same house edge: you get back p × d of each stake on average. That doesn't change because of what happened on the bets before, so over a whole session:
In the default example the house edge is 2.70%, the expected total wagered over 500 rounds is $6,016.99, and the expected result is -$162.62. The calculator gets the same number by adding up every possible outcome directly. Martingale makes you wager more (the bets grow after losses), so it can increase the expected loss compared with flat bets. You're ahead at the end 16.9% of the time, which is why it feels like it works.
Exact math, not just a simulation
After any round your position is fully described by two numbers: how many streaks you've finished and how many losses are in the current one. We track the probability of every such position round by round, so the bust chance and expected result are exact. The chart is a random simulation of the same rules, there to show what individual sessions look like. Common martingale calculators get this wrong in several ways:
- Calling a simulated percentage "exact", or giving a per-streak figure that ignores your bankroll.
- A fixed 1:1 payout with no house edge, which shows an expected value of zero for a game that loses money.
- Off-by-one bet ladders, where the stake listed for loss number 10 is really the 10th bet, not the one after it.
- No table limit, or no way to share the settings.
If you're using a system to chase losses, stop and set a limit. Our responsible gambling page has free support options.
Where to use it
Compare sites on our crypto casinos and CS2 betting sites lists. Check what a game keeps with the house edge calculator. Set a budget first, and see our responsible gambling page if it stops being fun.
FAQ
- Does the martingale strategy work?
- No. It wins small amounts often and loses a large amount occasionally, and with a house edge the average is a loss. In our default example (a $1,000 bankroll, $10 bets on red at a single-zero wheel, 500 rounds) the exact chance of going bust is 88.5% and the expected result is -$162.62.
- How many losses in a row can I survive with martingale?
- Add up the doubling bets until they pass your bankroll: $10 + $20 + $40 + ... With $1,000 and a $10 base you can place 6 bets ($630 in total); a 7th would need $640 and you only have $370 left. So 6 losses in a row end it.
- What is the probability of losing 10 times in a row?
- On an even-money roulette bet with a single zero, (19/37)^10 = 0.128% each time you start a streak, about 1 in 784. Over hundreds of rounds you start hundreds of streaks, so a long losing run becomes likely.
- Why do table limits beat martingale?
- The bets double, so a maximum bet caps how long a streak you can cover no matter how big your bankroll is. With a $10 base and a $5,000 limit you can place 9 bets in a row, even with $100,000 behind you.
- Is there a betting system that beats the house edge?
- No staking system changes the expected value of a bet. Each bet loses the house edge on average, so the expected result of any sequence is the edge times the total you wager. Systems only change how wins and losses are spread out.