Surebet (Arbitrage) Calculator
Detect arbitrage opportunities between bookmakers and lock in a guaranteed return.
Surebet (Arbitrage)
Set your total stake, calculate the guaranteed payout
Tennis, Basketball, BTTS, Over/Under...
📊 Odds by bookmaker
💡 Tip: click 🔓 next to an outcome to lock a stake already placed
📚 Full guide
Understanding Surebet
The holy grail: winning for sure by exploiting divergences between bookmakers
🎯What is a Surebet?▼
A Surebet (or arbitrage, or arb) is a combination of bets where you make money regardless of the event's result.
It's possible when two bookmakers have diverging odds: by taking the highest odds for each outcome at different bookmakers, the sum of implied probabilities can drop below 100%.
Golden rule: if RTP > 100%, profit is guaranteed. It's the grail — but it requires speed and several accounts.
💡A concrete example▼
Tennis match: Nadal vs Djokovic. Bookmakers disagree on the favorite.
Odds recorded:
🎾 Nadal at Betclic → odds 2.02
🎾 Djokovic at Unibet → odds 2.08
Sum of implied probabilities = 1/2.02 + 1/2.08 = 49.50% + 48.08% = 97.58%
RTP = 1 / 0.9758 × 100 = 102.48% → surebet!
Total stake: 100€
→ Stake 50.73€ on Nadal (Betclic)
→ Stake 49.27€ on Djokovic (Unibet)
Guaranteed payout ≈ 102.48€ (whoever wins) → profit +2.48€ (2.48%)
Real surebets run between 1% and 5%. Above that, it's suspicious (input error or stale odds).
⚙️Advanced options: Commissions, Back/Lay, Lock, Rounding▼
💱 Commissions
Enable this option if you use a betting exchange like Betfair (5%), Smarkets (2%) or Matchbook (1.5%). The commission is taken on winnings — the calculator adjusts the stake automatically.
🔄 Back / Lay per outcome
By default, all your stakes are Back (you bet FOR an outcome). Enable Back/Lay to model a Lay bet (AGAINST an outcome) on an exchange. Lets you build cross-bookmaker/exchange arbs. For each Lay, the calculator also shows the liability (funds to block on the exchange).
🔒 Fixed stake (lock)
Already placed a stake and want to calculate how much to stake on the other outcomes? Click the padlock 🔓 next to an outcome, enter the stake already placed, and the calculator automatically recalculates the other stakes around it. Essential to catch up a bet.
📐 Stake rounding
Some bookmakers impose a minimum per increment (0.50€, 1€, even 5€). The calculator rounds automatically and shows you the profit loss due to rounding.
🔀Dutching vs Surebet▼
⚖️ Dutching
A single bookmaker, you spread across several outcomes of the same event. The RTP generally stays below 100% (the book's margin).
🎯 Surebet
Several bookmakers, you exploit their odds divergences. The RTP goes above 100% → guaranteed profit.
Key difference: Dutching handles the choice between favorites, Surebet exploits market inefficiency.
📖Terms to know▼
RTP (Return To Player)
1 / Σ(1/odds) × 100. If > 100%, it's a surebet.
Arbitrage margin
RTP - 100. Guaranteed profit as % of the total stake.
ROI %
Profit / total stake × 100. Equivalent to the arbitrage margin.
Guaranteed payout
The amount recovered whatever the outcome (identical).
Back / Lay
Back = bet FOR an outcome (bookmaker). Lay = bet AGAINST an outcome (exchange like Betfair).
Liability
For a Lay: max amount you can lose if the outcome happens. To have available on the exchange.
Arbing
Placing surebets on a recurring basis.
🔢Step-by-step guide▼
Choose the market: 2 outcomes (tennis, BTTS, O/U), 3 outcomes (football 1X2) or 4 outcomes (golf, hockey, races)
Choose the mode: Total stake or Target profit
Enable Commissions if you use an exchange (Betfair 5%, Smarkets 2%)
Enable Back/Lay to combine a classic bet + a lay on an exchange
For each outcome, enter the highest odds + the bookmaker name
Check the RTP: > 100% = surebet → guaranteed profit
Place the stakes in the suggested order (highest odds first)
Copy the recap to keep a record
⚠️The limits of Surebet▼
🚨 Account limitation
Bookmakers quickly detect arbers and limit your stakes (sometimes to 1€). THE main risk.
⚡ Odds that move
Odds change continuously. If the 2nd odd drops before you can stake, the surebet becomes losing.
💸 Multi-accounts needed
You need accounts opened and funded at several bookmakers, which ties up capital.
🎰 Match cancelled / refunded
If a match is cancelled at one bookmaker (stake refunded) but not the other, the surebet breaks.
📊 Low margins
Real surebets run at 1-3%. To make 100€/month you must stake large volumes.
Pro tips
📌 A surebet of 1-5% is normal — beyond that, check your odds
📌 Place the bets as fast as possible, odds move
📌 Start with the most volatile odd — the calculator gives you the order
📌 Vary the stakes to avoid getting limited (avoid round amounts)
📌 Favor major events (liquidity), avoid obscure leagues
📌 For cross-exchange Back/Lay surebets: always keep the liability available
📌 Keep a margin on each account to absorb variations
📌 Value bet > Surebet in the long run if you don't get limited