Sports Betting Arbitrage Calculator
Compare Book A/B/C odds in five formats, calculate a theoretical stake split, and test entered cost, rounding and slippage assumptions before using the result.
Sports betting maths path
Know what this result can—and cannot—tell you
Current check
Arbitrage Calculator
Test whether a price gap survives execution costs.
Optional risk branches · Recommended next check
Bankroll Risk Calculator
Stress-test the candidate stake against the bankroll.
View the complete calculation path
- 1Odds Converter
- 2Bet Calculator
- 3Vig / Margin Calculator
- 4Expected Value Calculator
- 5Kelly Criterion Calculator
- 6Bankroll Risk Calculator
- 7Losing Streak Risk Simulator
- 8Profit and Stop-Loss Planner
Optional risk branches
Use these only for cross-book execution or to inspect how a staking progression can fail.
Surebet detector
Cross-book surebet detector
Two-Way, Three-Way and Asian Handicap markets share one engine — every input format is normalised to Decimal odds, then implied probabilities are summed. Anything under 100% is an arb.
The prefilled prices are a worked example. Replace every outcome with current prices for the same event, market and settlement rules.
Tap the amount above to change it. Stakes split across every leg — profit and allocation on the right update instantly.
Decimal remains the main display format. HK odds are common in Asia; Malay odds use values between -1.00 and +1.00, such as +0.90 or -0.90. Indonesian odds use values at or beyond ±1.00, such as +1.20 or -1.20. Keep the sign — every price is converted to Decimal before BEST is selected.
On mobile, copy the odds from one sportsbook first, then the next. The calculator still picks the best Decimal-converted price for each outcome automatically.
The entered implied probabilities total below 100%. This is a mathematical result before costs, price acceptance, market matching and settlement.
Change total stake on the left to update the theoretical result and stake split.
How is this arb calculated?
The calculator converts every price to Decimal odds, turns each outcome into implied probability, then checks whether the market totals under 100%.
- 01Implied probability = 1 ÷ Decimal odds.
- 02Add every outcome's implied probability. If the total is below 100%, a surebet exists.
- 03Stake share = each implied probability ÷ the total, so every outcome returns a similar payout.
1/2.10 = 47.62% · 1/2.05 = 48.78%
Stake split — exact dollars per leg
The bar below allocates your total stake to each leg in proportion to that leg's implied probability so all outcomes return the same dollar amount. The table beneath spells out the stake, gross payout and share for every leg.
| Book | Outcome | Stake | Payout | Share |
|---|---|---|---|---|
| Book A | Home | $493.98 | $1037.35 | 49.4% |
| Book B | Away | $506.02 | $1037.35 | 50.6% |
Pre-bet execution check
Surebets fail in the real world when prices move, fees bite or stakes need rounding. Stress-test slippage, costs and rounded stake units before you click both bets.
Advanced execution settingsOptional: adjust stake rounding, costs and odds slippage before placing bets.
The fine print
What the formula cannot verify
The calculator evaluates only the odds and assumptions you enter. Verify the live market, acceptance and settlement conditions separately.
Bookmaker limits & account flags
Stake limits and account rules vary by operator, market, product and jurisdiction. Check the current operator terms before placing either leg.
Stale odds & line moves
The calculator cannot tell whether a quoted price is current. Recheck every leg immediately before placing a bet and recalculate if any price changes.
Leg-execution & void risk
If one leg confirms but the other suspends, voids or pushes, you no longer have a locked return. Be extra careful with whole-number Asian Handicap lines.
Capital lock-up & opportunity cost
Balances, transfer costs and withdrawal conditions can differ across operators. Include any known costs in the execution panel and review the relevant terms.
The honest takeaway
Treat a positive result as a prompt to verify the inputs, not as proof of a settled outcome. Compare the entered market margin and recalculate whenever a price or cost changes.
Math + reality
How to read your result
Use these quick rules after the calculator gives you a number. The goal is not just finding an arb — it is deciding whether the edge is still usable.
First check: are the inputs equivalent?
Confirm that every leg covers the same event, market, participant set and settlement rule. A large calculated edge does not prove that a price is current or that both bets will be accepted.
Second check: can you place every leg?
Use the stake split only if all legs are open, limits are high enough and the odds still match the screen. If one leg needs rounding, recheck the net profit after rounding and cost.
Third check: what is still unknown?
The tool does not check operator terms, local law, account eligibility, withdrawal conditions or the final settlement. Verify those items from current official sources.
How it works
Three steps to test entered odds
Use the calculator in three moves: pick the market, enter the prices you see, then check whether the split still works after fees and line movement.
- 1
1. Pick the market and enter the odds
Choose Two-Way, Three-Way or Asian Handicap, then enter the prices exactly as your sportsbook shows them.
- 2
2. Set your total stake — splits update live
Change the total stake and the calculator instantly splits it across the winning prices for each outcome.
- 3
3. Read the arb % and ROI
Check the arb edge and theoretical ROI, then use the execution panel to see how your rounding, cost and slippage assumptions change the result.
Why arbing is hard
An arb is a mathematical gap in entered prices
Two sportsbooks can price the same market differently: A shows 2.10 on Home and B shows 2.05 on Away. 1/2.10 + 1/2.05 ≈ 0.964, so the entered implied probabilities total less than 100%. The 3.6% shortfall is the mathematical arb edge before costs, price acceptance and settlement differences.
The math is the easy part — stake split is where the real work is
Knowing an arb exists is one thing; sizing each leg so the return is identical no matter who wins is another. The Stake Split bar below allocates dollars proportional to each leg's implied probability, so the payout ladder is flat — you get the same money back whether Home wins, Away wins, or (in 3-way markets) it's a draw.
The formula works only on matching inputs
The calculator cannot verify whether both prices are still available, whether both legs use identical settlement rules, whether each stake will be accepted or whether fees apply. Enter the same event and market on every leg, then verify current prices, limits and terms before acting.
Results depend entirely on the odds, stake and cost assumptions you enter. The calculator does not verify live prices, market equivalence, bet acceptance, account eligibility, local law, operator terms or settlement. Book A / B / C are neutral labels and no operator quote is collected or endorsed.
Compare current terms before choosing a sportsbook
The calculator does not verify live odds, market rules, fees, limits, identity checks, withdrawals or settlement. If you are comparing XYES with another sportsbook, review each operator's current official terms and recalculate using the prices and costs that apply to you.
Common questions about arbitrage betting, surebets and stake splits
Quick answers about jurisdiction limits, operator terms, odds formats, market matching and what the calculation cannot verify.
Is arbitrage betting legal?
Why do bookmakers limit arbitrage bettors?
Can I enter Malay or Indonesian odds directly?
Do two-way, three-way and Asian Handicap arbs use different formulas?
Can I use this for football, tennis and basketball?
What arb edge is worth betting after fees and line movement?
Should I do arbitrage or value betting?
Other checks if you need them
Use the calculation in the right betting context
The tool handles one mathematical task. These guides explain the market, settlement and risk assumptions around that result.
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