Double Bet (Martingale) Calculator
Use this tool to model a classic double-up progression: after each loss, the next stake doubles. Enter your values to see bankroll requirements, projected payout, and a full round-by-round table.
What is a double bet strategy?
A double bet strategy (often called a Martingale progression) increases your stake after each loss, usually by a factor of 2. The goal is simple: when a win finally happens, that single win can recover prior losses and (in some cases) leave a small profit.
This approach is popular in sports betting and casino discussions because it feels mathematically neat. However, it demands a rapidly increasing bankroll and can break down under realistic limits such as table caps, betting limits, market shifts, and losing streak probability.
How this calculator works
Inputs
- Starting Bet: your first wager in the sequence.
- Decimal Odds: payout multiplier on a win (stake included).
- Losses Before Win: how many consecutive losses happen before your next win.
- Available Bankroll: optional check to see if your sequence is affordable.
Core math
For round n, stake is:
Stake(n) = Starting Bet × 2^(n-1)
Total amount risked through the winning round is the sum of every stake up to that point. Net result if you win in a given round is:
Net = (Winning Stake × Decimal Odds) − Cumulative Stakes
Why odds matter more than most people expect
At 2.00 odds, a strict doubling progression often returns roughly one starting unit of profit when the win arrives. But if odds are lower than 2.00, the same doubling pattern may not fully recover losses at later rounds. That is why this calculator shows net profit/loss directly instead of assuming all outcomes are equal.
If you use odds significantly above 2.00, a win can return more than a single unit—but higher odds also generally imply lower win probability. In short, payout and probability must be considered together.
Bankroll planning and risk control
How quickly stakes grow
Doubling produces exponential growth. A small starting bet can become very large in just a few rounds. For example, starting at $10:
- Round 1: $10
- Round 2: $20
- Round 3: $40
- Round 4: $80
- Round 5: $160
The required bankroll is the sum of all these bets, not just the last one.
Practical safeguards
- Set a hard maximum number of rounds before starting.
- Never scale your starting stake based on recent losses.
- Track total exposure, not just individual bet sizes.
- Remember that long losing streaks are rare, but not impossible.
Frequently asked questions
Does doubling guarantee profit?
No. It can fail due to bankroll limits, betting caps, and odds that do not support full recovery.
Is this only for sports betting?
No. The math applies to any repeated wager structure where you can define odds and sequence outcomes.
What is the biggest mistake users make?
Underestimating exponential growth in required capital. Most failures come from running out of bankroll before the expected win appears.
Final thought
A double bet calculator is best used as a risk visualization tool. If it helps you see how fast exposure climbs, it has done its job. Plan your limits first, run your numbers second, and avoid strategies you cannot fund safely.