Sure Bet Calculator
Calculate arbitrage opportunities and guaranteed profit from different bookmakers
Formula:Arb% = 100 - Σ(1/odds × 100)
Market Setup
Configure the arbitrage calculation
$
Odds from Different Bookmakers
Enter the best odds available for each outcome
Arbitrage Found!
6.93% guaranteed profit opportunity
Guaranteed Profit
$74
7.44% return on $1,000
Optimal Stake Distribution
Outcome 1@ 2.20
45.45% impliedStake: $488
Returns: $1,074
Profit: $74
Outcome 2@ 2.10
47.62% impliedStake: $512
Returns: $1,074
Profit: $74
Total Stake
$1,000
Arbitrage %
6.93%
Guaranteed Profit
$74
ROI
7.44%
Important: Place all bets as quickly as possible. Odds can change at any moment, eliminating the arbitrage opportunity. Check betting limits at each bookmaker before placing your bets.
Try These Examples
Common arbitrage scenarios
Arbitrage Bet Tracker
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How Sure Bets Work
Understanding arbitrage betting
Step-by-Step Example
- 1. Find odds: Player A wins @ 2.20 (Bookmaker 1), Player B wins @ 2.10 (Bookmaker 2)
- 2. Calculate implied probability: (1/2.20) + (1/2.10) = 45.45% + 47.62% = 93.07%
- 3. Confirm arbitrage: 93.07% < 100% = Yes! Arbitrage exists
- 4. Calculate stakes: On $1000 total: $488.37 on A, $511.63 on B
- 5. Guaranteed profit: Either outcome returns ~$1074.42 = $74.42 profit
Arbitrage Formula
Arb% = 100 - (100/odds1 + 100/odds2)
If result > 0, arbitrage exists
Stake Formula
Stake = TotalStake × (1/odds) / Σ(1/odds)
Ensures equal returns regardless of outcome
Quick Answer
TL;DR summary
A sure bet (arbitrage) exists when the combined implied probabilities from different bookmakers total less than 100%. For two outcomes with decimal odds 2.20 and 2.10: Implied Prob = (1/2.20) + (1/2.10) = 45.45% + 47.62% = 93.07%. Since 93.07% < 100%, this is a 6.93% arbitrage. On a $1000 total stake, you'd profit ~$69.3 guaranteed.
Key Facts About Sure Bets
Important things to know
- Arbitrage exists when total implied probability < 100%
- The profit margin equals 100% minus total implied probability
- Stakes must be distributed inversely to odds to guarantee equal returns
- Sure bets typically offer 1-5% profit margins
- Bookmakers actively limit arbitrage bettors
- Odds can change quickly - execute both sides immediately
- Account for betting limits when calculating maximum arbitrage profit
- Different bookmaker limits may prevent optimal stake distribution
Frequently Asked Questions
Common questions about arbitrage betting
What is a sure bet or arbitrage?
A sure bet (also called arbitrage, arb, or surebet) is a betting strategy where you place bets on all possible outcomes of an event across different bookmakers, guaranteeing a profit regardless of the result. This works when the combined implied probabilities of all outcomes total less than 100%.
How do I calculate if an arbitrage opportunity exists?
Convert all odds to implied probabilities (1/decimal odds × 100), then sum them. If the total is less than 100%, an arbitrage exists. The profit percentage equals 100% minus the total implied probability. For example, if outcomes sum to 95%, you have a 5% guaranteed profit margin.
How much should I stake on each outcome?
Stake inversely proportional to the odds to guarantee equal returns. Stake on Outcome A = (Total Stake × Implied Prob of A) / Total Implied Probability. This ensures you win the same amount regardless of which outcome hits.
Why do bookmakers allow arbitrage?
Bookmakers don't intentionally allow it - arbitrage opportunities arise from price discrepancies between different bookmakers. Each bookmaker prices events independently based on their own liability and information. These gaps create temporary arbitrage windows.
What are the risks of arbitrage betting?
Risks include: account limitations/closures by bookmakers, odds changing before placing all bets, palpable error rules voiding winning bets, and betting limits preventing optimal stakes. Always read bookmaker terms carefully.
How much profit can I expect from arbitrage?
Typical arbitrage opportunities offer 1-5% profit margins. A 3% margin on $1,000 total stake yields $30 profit. While individual profits are small, they're guaranteed. Professional arbers may process hundreds of bets monthly.
How this works
Calculations follow the published mathematics of the game — combinatorics for cards, probability theory for dice, and expected-value accounting for wagers. Results are verified against independent references (primarily Wizard of Odds). No calculation here is an opinion or recommendation; it is arithmetic applied to the rules of the game.
What this tool can’t do
When to consult a professional
This tool computes probability and expected value. It is not a betting system and cannot predict the outcome of any individual wager. If gambling is causing problems for you or someone you know, call the National Problem Gambling Helpline at 1-800-GAMBLER.
Sources
- [1]Wizard of Odds — Michael Shackleford, ASAIndustrywizardofodds.comAccessed Apr 21, 2026
Actuary; widely cited casino-game probability reference. Used for house-edge and EV verification.
- [2]National Council on Problem GamblingOfficial sourcencpgambling.orgAccessed Apr 21, 2026
Responsible-gambling guidance and 1-800-GAMBLER helpline.
Joseph OrdunaFounder & Software Engineer
Full-stack software engineer specializing in embedded systems, web architecture, and AI/ML. Founder of Practical Web Tools. Built the gesture-controlled drone IP acquired by KD Interactive (Aura Drone, sold on Amazon).