Martingale Calculator: See Why the System Fails
A free Martingale calculator that shows the doubling progression, risk of ruin, and bankroll exhaustion for any starting bet. See exactly how many losses it takes to wipe out your bankroll.
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Martingale Progression Table
| Round | Bet Amount | Total Invested | Profit if Win | Status |
|---|---|---|---|---|
| 1 | $10.00 | $10.00 | $10.00 | ✓ |
| 2 | $20.00 | $30.00 | $10.00 | ✓ |
| 3 | $40.00 | $70.00 | $10.00 | ✓ |
| 4 | $80.00 | $150.00 | $10.00 | ✓ |
| 5 | $160.00 | $310.00 | $10.00 | ✓ |
| 6 | $320.00 | $630.00 | $10.00 | ✓ |
| 7 | $640.00 | $1,270.00 | $10.00 | ⚠️ >50% bankroll |
| 8 | $1,280.00 | $2,550.00 | — | 💀 BANKRUPT |
| 9 | $2,560.00 | $5,110.00 | — | 💀 BANKRUPT |
| 10 | $5,120.00 | $10,230.00 | — | 💀 BANKRUPT |
| 11 | $10,240.00 | $20,470.00 | — | 💀 BANKRUPT |
| 12 | $20,480.00 | $40,950.00 | — | 💀 BANKRUPT |
| 13 | $40,960.00 | $81,910.00 | — | 💀 BANKRUPT |
| 14 | $81,920.00 | $163,830.00 | — | 💀 BANKRUPT |
| 15 | $163,840.00 | $327,670.00 | — | 💀 BANKRUPT |
⚠️ Why Martingale Fails
With a $1,000.00 bankroll and $10.00 initial bet, you can only survive 6 consecutive losses.
Over just 100 bets, there is a 82.76% chance of hitting that losing streak and going bust.
Every winning round only nets the initial bet ($10.00), but a single ruin event wipes out $2,550.00+.
The house edge of 2.70% means you lose an expected $27.00 over 100 flat bets. Martingale doesn't change the math — it only concentrates losses into rare, catastrophic events.
How Martingale Works
After each loss, double the bet. After a win, reset to the initial bet. The idea is that one win recovers all previous losses plus the initial bet profit.
- Bet at round n — initial_bet × 2n−1
- Max losses before ruin — ⌊log₂(bankroll / initial_bet)⌋
- Ruin probability (N bets) — 1 − (1 − qmaxLosses)N − maxLosses + 1
- EV per bet — initial_bet × (p × payout − 1)
No betting system can overcome a negative expected value. Martingale trades many small wins for rare catastrophic losses — the expected value remains exactly the same as flat betting.
The Martingale system is mathematically guaranteed to fail given a house edge and finite bankroll. This calculator demonstrates why "just double it" is the most dangerous myth in gambling.
The short answer
The calculator above shows what actually happens when you double your bet after every loss. Enter your starting bet, bankroll, and the game's win probability — and watch the progression table turn red. The Martingale system doesn't fail because of bad luck. It fails because of math.
Key takeaway: A $10 Martingale on European roulette (48.65% win probability) with a $1,000 bankroll can survive at most 6 consecutive losses before ruin. The probability of hitting 6+ losses in a row during a 100-bet session is roughly 22%. That's not a freak event — it's expected to happen about once every 5 sessions.
How to use the calculator
- Set your initial bet — the amount you start with after a win or at the beginning.
- Choose a preset or set custom odds — European roulette (48.65%), American roulette (47.37%), or coin flip (50%).
- Enter your bankroll — total amount available.
- Read the progression table — each row shows the bet size doubling after a loss. Green rows are affordable, red rows exceed your bankroll.
- Check the ruin stats — how many losses you can survive, the probability of hitting that streak, and the expected outcome over time.
How the Martingale works (in theory)
The idea is simple: double your bet after every loss, so when you finally win, you recover all previous losses plus one unit of profit. After any win, return to the starting bet.
On paper it sounds foolproof. In practice, the doubling creates exponential growth that hits your bankroll limit or the table limit far sooner than most people expect. A $10 starting bet reaches $1,280 after just 7 doublings — and you've already invested $2,540 total to win $10 of profit.
Why it always fails
Three forces kill the Martingale:
1. Exponential bet growth. Each loss doubles the bet. After 10 losses, a $10 bet has become $10,240. The growth is 2^n — it's not linear, it's explosive.
2. Finite bankroll. No bankroll is infinite. The calculator shows exactly which round your bankroll runs out. For most players, that's round 6-8 with a reasonable starting bet.
3. Negative expected value. On every spin of European roulette, the house has a 2.70% edge. The Martingale doesn't change this. It just rearranges when you experience the loss — many small wins punctuated by one catastrophic wipe. The expected value per round is still negative: initial_bet × (2p − 1), which is always negative when p < 50%.
For the full argument with worked examples, see our article on why roulette systems don't work. The roulette betting systems lesson covers the same material in the course.
The risk of ruin is higher than you think
Most players imagine losing 7+ in a row as incredibly unlikely. The calculator shows the real probability. On European roulette, the chance of 7 consecutive reds or blacks not hitting is (19/37)^7 ≈ 1.1%. Sounds safe, right?
But over 100 bets, the chance of hitting a streak of 7 at some point jumps to roughly 15-25% (depending on the exact calculation). Over a weekend of play (500+ bets), it's almost guaranteed. The Martingale doesn't eliminate risk — it concentrates it into rare but devastating events.
For more on why even-money bets aren't truly even, see red or black odds. And for an honest assessment of all roulette payouts, try the roulette payout calculator.
What should I learn next?
- Roulette Systems: Why They Don't Work: The full mathematical case against all betting systems
- Red or Black Odds: Why even-money roulette bets aren't 50/50
- Roulette Payout Calculator: Calculate exact payouts and expected loss
- Kelly Criterion Calculator: The only mathematically sound bet-sizing system
- Craps Betting Systems: The same myth-busting for craps
About the author
Trust & Responsible Play Writer
Marcus focuses on judging casinos before you deposit — licensing checks, red flags, scam patterns — and the bankroll habits and limit tools that keep play under control.