Arbitrage Betting Calculator
Our arbitrage betting calculator checks whether the best odds on every outcome add up to less than 100% and, if they do, splits your naira stake so every result pays the same.
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The arbitrage betting calculator tells you whether a set of prices from different bookmakers covers every outcome for less than you would get back. If it does, the tool splits your total stake so the return is the same whatever happens. If not, it shows how far above 100% the combined book sits.
What an arbitrage bet is
Each bookmaker builds a margin into its prices, so its own odds on all outcomes always add up to more than 100% in implied probability. Different bookmakers, however, sometimes disagree. When you take the highest price for each outcome from different sites, the total can occasionally drop below 100%. That gap is an arbitrage, often called a “sure bet” or “arb”.
This is not the same thing as the “sure win” tips sold on social media. An arb does not predict anything; it is a pricing gap. Those tips are predictions with risk, as our page on why sure wins do not exist explains.
How to use the arbitrage betting calculator
- Choose 2-way or 3-way. Two-way covers markets such as over/under 2.5 or a tennis match winner. Three-way covers 1X2 (home, draw, away).
- Enter the best odds for each outcome. Usually each comes from a different bookmaker.
- Enter your total stake. The amount you want spread across all outcomes, for example ₦10,000.
- Read the arb %. Below 100 means an arbitrage exists; the tool then shows each stake, the return, profit and ROI.
The arbitrage formula
- Arb % = (1 ÷ odds A + 1 ÷ odds B + …) × 100. Each term is that price’s implied probability, which the implied probability calculator shows on its own.
- Stake on each outcome = total stake × (1 ÷ its odds) ÷ the sum of all 1 ÷ odds.
- Return = total stake ÷ the sum of all 1 ÷ odds, the same for every outcome.
- Profit = return − total stake, and ROI = profit ÷ total stake × 100.
If the arb % is 100 or more, the calculator shows “No arbitrage” and how many points above 100 the prices sit. To see how much margin a single bookmaker is charging, use the bookmaker margin calculator instead.
Worked examples in naira
Example Over 2.5 goals at 2.10 with bookmaker A and under 2.5 at 2.05 with bookmaker B, total ₦10,000. Arb % = (1 ÷ 2.10 + 1 ÷ 2.05) × 100 = 47.62 + 48.78 = 96.4%. Stakes: ₦4,940 on over and ₦5,060 on under. Return ≈ ₦10,373 either way (₦4,940 × 2.10 = ₦10,374; ₦5,060 × 2.05 = ₦10,373 after rounding), profit ≈ ₦373, ROI 3.7%.
Example A 1X2 market with home 2.30, draw 3.50 and away 3.80 at three different sites, total ₦20,000. Arb % = 43.48 + 28.57 + 26.32 = 98.4%. Stakes: ₦8,840 home, ₦5,809 draw, ₦5,351 away. Each result returns about ₦20,332, a profit of ₦332 (1.7%).
Most prices you compare will not qualify. Over at 1.90 and under at 1.95 add up to 103.9%: the calculator reports no arbitrage, 3.9 points above 100. Split ₦10,000 the same way there and you would get back only about ₦9,623 whatever the score.
The risks the “risk-free” label hides
The maths is certain; the betting is not. Before you try it, know what can go wrong:
- Odds change between bets. You place the first leg, and by the time you open the second app the price has dropped. You are now holding a normal bet with no cover. Prices on live and popular markets move in seconds.
- Palpable error voids. Arbs often appear because one bookmaker posted a wrong price. Most bookmaker terms let them void or resettle bets at obviously mistaken odds, which can leave your other leg standing alone.
- Account limits. Bookmakers watch for accounts that only bet on out-of-line prices. Stake limits or restrictions can follow quickly, and arbs need several healthy accounts.
- Different settlement rules. One site may void a bet if a match is abandoned or postponed while another keeps it open for longer, or settle a market differently. Read the rules for each market.
- Uneven coverage. Pairing home draw no bet with an away win leaves the draw half-covered; pairing home win with away win misses the draw completely. Every outcome must be covered exactly once.
- Small margins, real costs. A 2% arb on ₦20,000 is ₦400. Deposit and withdrawal fees, rounded stakes or a single mistake can erase several weeks of arbs.
Place the leg at the price most likely to move first, usually the out-of-line bookmaker, and check every ticket before you confirm the next one. Never assume an arb is still there after a slip has been rejected or re-priced.
Arbitrage vs dutching and hedging
Arbitrage covers every outcome and only works when the combined book is below 100%. The dutching calculator uses the same stake-splitting maths on a chosen subset of outcomes, so you can still lose. The hedge bet calculator is for bets you placed earlier, when the price on the other side has moved in your favour.
Is arbitrage betting worth it in Nigeria?
It can work for patient punters with accounts at several licensed bookmakers (see our list of Nigerian betting sites), quick deposits and careful record keeping. The profits per bet are small, the work is repetitive, and account limits mean it rarely lasts. Treat any arb calculator result as the start of a check, not the end of one.
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Frequently asked questions
Clear arbs are not common and usually last only minutes, because bookmakers adjust prices once money arrives or a price is corrected. They show up more on less popular leagues and markets where bookmakers set prices independently. Expect many comparisons for each real opportunity.
A bookmaker can void a bet under its palpable error rules if the price was clearly wrong, and it can restrict an account. It should not cancel a bet just because you also bet elsewhere, but check each operator's terms. A voided leg turns your arb into an ordinary single bet.
Many arbers ignore anything above about 99%, because a 1% profit disappears with one rounding error, fee or price change. Arbs between roughly 95% and 98% are more worthwhile, but very low figures often signal a mistaken price that may later be voided.
Rounding to the nearest ₦10 or ₦50 makes stakes look less unusual and is easier to type quickly. It shifts each outcome's return by a few naira, so recheck that every leg still returns more than your total stake after rounding.
Placing bets with licensed bookmakers is legal for adults, and comparing prices across them is not against the law. Bookmakers can still set their own account rules and limits. Read our guide on Nigerian betting law and licensing for the regulator side.