Arbitrage Bet Calculator
Enter decimal odds from different sportsbooks and your total bankroll for this opportunity. The calculator will split stakes to equalize payouts.
Tip: Arbitrage exists when the sum of implied probabilities is less than 100%.
What this gambling arbitrage calculator does
A gambling arbitrage calculator helps you distribute bets across all outcomes of an event so that your payout is nearly equal no matter what happens. If the combined implied probability from all selected odds is below 100%, that setup is an arbitrage opportunity (often called an "arb"), which can create a mathematically positive edge.
In practical terms, this tool answers one question quickly: "How much should I place on each side?" It removes manual math errors and gives you stake sizing, expected payout, and estimated profit.
How arbitrage works (simple formula)
Step 1: Convert odds to implied probability
For decimal odds, implied probability is:
Probability = 1 / Decimal Odds
Example: odds of 2.10 imply 1 / 2.10 = 47.62%.
Step 2: Add all implied probabilities
If the total is:
- Less than 100% → positive arbitrage may exist.
- Equal to 100% → break-even before rounding/friction.
- Greater than 100% → no guaranteed profit.
Step 3: Split stake proportionally
The calculator allocates your bankroll using:
Stake on outcome i = Total Stake × (1 / oddi) / Sum of implied probabilities
This equalizes the return from each outcome as closely as possible.
How to use this calculator effectively
- Use decimal odds from reliable sportsbooks or exchanges.
- Enter either 2 outcomes (most head-to-head markets) or 3 outcomes (e.g., soccer home/draw/away).
- Set your total stake based on your bankroll limits and risk controls.
- Place all bets quickly—odds can move in seconds.
- Double-check max stake limits and minimum bet sizes before committing.
Important real-world constraints
Even when the math is correct, real execution can reduce or erase expected profit:
- Odds movement: one side may shift before your second bet is placed.
- Stake limits: books may not allow the full required amount.
- Rules mismatch: overtime, void conditions, or settlement policies may differ by bookmaker.
- Account restrictions: successful arbitrage bettors are often limited.
- Fees/taxes: exchange commission, payment fees, or local taxes can matter.
Bankroll and risk management checklist
Before betting
- Keep a dedicated bankroll, separate from essential funds.
- Set a per-arb maximum exposure and daily cap.
- Track every bet with timestamp, market, and book.
During execution
- Place the most fragile side first (usually the side likely to move).
- Confirm bet acceptance and ticket status for each leg.
- Avoid low-liquidity markets where partial fills are common.
After settlement
- Reconcile expected vs. actual return.
- Log any rule discrepancies for future filtering.
- Review ROI net of fees and failed arbs.
Frequently asked questions
Is arbitrage betting risk-free?
The math can be risk-reduced, but execution risk is real. Delays, limits, and rule differences create practical risk.
Can I use American or fractional odds?
This page is built for decimal odds. Convert your odds first for accurate results.
How much ROI is typical?
Many opportunities are small (often under a few percent). Consistency and execution quality matter more than one big edge.
Final note
Use this gambling arbitrage calculator as a decision aid, not a guarantee. Always verify local laws, bookmaker terms, and responsible gambling guidelines in your jurisdiction.