Surebet Calculator

Q: What is the difference between 2-Way and 3-Way market types?

A 2-Way market has two possible outcomes, like a tennis match or an over/under bet. A 3-Way market has three possible outcomes, like a football match where the home team can win, the away team can win, or the game can end in a draw.

Q: What is the difference between Win and Bet commission types?

Win commission is taken only from your profit when your bet wins. Bet commission is taken from the full amount you wager, win or lose. Betting exchanges like Betfair typically use win commission.

Surebet Calculator

Updated Jul 18, 2026 By Jehan Wadia

Introduction

A surebet happens when the odds from different bookmakers let you bet on every outcome of a game and still make a profit no matter who wins. This is also called arbitrage betting. It works because not all bookmakers agree on the same odds, and sometimes the gap between them is big enough to guarantee you money.

This free surebet calculator does the math for you. Enter the odds for each outcome, and it will tell you if a surebet exists. If one does, it shows you exactly how much to stake on each side to lock in a guaranteed profit. The tool supports 2-way markets like tennis or over/under bets, and 3-way markets like football match results that include a draw. You can use decimal, fractional, American, Hong Kong, or Indonesian odds formats. It also handles exchange commissions so your results stay accurate.

The calculator breaks down every step of the math so you can see how it works. It shows your implied probability total, profit margin, return on investment, and the exact stake to place on each outcome. Use it to spot real arbitrage opportunities and size your bets with confidence.

How to Use Our Surebet Calculator

Enter your odds from different bookmakers for the same event. The calculator will tell you if a surebet exists, how much to stake on each outcome, and your guaranteed profit.

Market Type: Pick 2-Way for events with two outcomes, like tennis or over/under bets. Pick 3-Way for events that include a draw, like football match results.

Odds Format: Choose the format your bookmaker uses. Options include Decimal, Fractional, American, Hong Kong, and Indonesian. The calculator converts all formats automatically. If you need to convert between fractional and decimal values outside of this tool, a decimal to fraction calculator can help.

Currency: Select your preferred currency. This changes the symbol shown next to all money values in the results.

Total Stake: Enter the total amount of money you want to bet across all outcomes. Select "Fix total stake" to let the calculator split this amount for you.

Bookmaker: Type the name of the bookmaker offering the odds for each outcome. This field is optional.

Odds: Enter the odds each bookmaker gives for that outcome. Use the format you selected above. If you want to compare odds across formats or understand what your odds mean in terms of payouts, try our betting odds calculator.

Commission Type: Choose Win if your bookmaker charges commission only on winnings. Choose Bet if commission applies to the full bet amount.

Commission %: Enter the commission percentage your bookmaker charges. Leave it at 0 if there is no commission. Our percentage calculator can help you verify commission amounts if needed.

Include This Leg: Uncheck this box to remove an outcome from the calculation without deleting its data.

Fix This Stake: Select this option on any outcome to lock that stake amount. The calculator will then adjust all other stakes and the total stake around it.

Round to Nearest: Choose how to round each stake. This helps when a bookmaker does not accept bets with small decimal amounts.

Press Calculate to see your results. Press Reset Calculator to return all fields to their default values.

What Is a Surebet?

A surebet happens when two or more bookmakers offer odds on the same event that, when combined, guarantee you a profit no matter who wins. This is also called arbitrage betting. The key idea is simple: the odds from different bookmakers disagree enough that you can bet on every possible outcome and still come out ahead. For a broader look at how arbitrage works across financial markets, see our arbitrage calculator.

How Does a Surebet Work?

Every set of odds has a built-in implied probability. This is how likely the bookmaker thinks an outcome is. In a normal market, the implied probabilities for all outcomes add up to more than 100%. The extra amount is the bookmaker's edge. But sometimes, if you pick the best odds from different bookmakers, those probabilities add up to less than 100%. When that happens, you have found a surebet. The gap below 100% is your guaranteed profit margin. To understand how bookmakers build that edge into their odds, our no vig calculator strips the margin away and shows the true implied probabilities.

How to Use This Surebet Calculator

This calculator does all the math for you. Enter the odds for each outcome, choose your total stake, and it tells you exactly how much to bet on each side. It also shows whether a surebet exists, what your guaranteed profit will be, and your return on investment (ROI). You can switch between 2-way markets like tennis or over/under totals and 3-way markets like football match results that include a draw.

Understanding Effective Odds and Commission

Some betting exchanges charge a commission on your winnings or your total bet. This lowers your real payout. The calculator adjusts for this by computing effective odds, which are your true odds after the commission is taken out. Always enter any commission your platform charges so the results stay accurate. Use our margin calculator to double-check how commissions affect your overall profit margins.

Why Surebets Are Rare

Bookmakers watch their odds closely and adjust them fast. Surebet chances usually last only minutes. Odds also shift as people place bets. Because of this, speed matters. You need to spot the opportunity, calculate your stakes, and place all bets before the odds change. This calculator helps you act quickly by giving you instant results as you type. You can also use our odds calculator to quickly evaluate individual lines, and our probability calculator to verify implied chances across outcomes.

Important Things to Keep in Mind

Surebet profits are usually small, often between 1% and 5% of your total stake. Bookmakers may also limit or close accounts that consistently place arbitrage bets. Always read the terms and conditions of any bookmaker you use. This calculator is a math tool. It shows you the numbers but does not guarantee that odds will stay the same long enough for you to place every bet. If you are interested in other betting strategies, our parlay calculator helps you evaluate multi-leg accumulators, our bet calculator handles standard single and combination wagers, and our EV calculator can help you assess the expected value of any bet before you place it.

Formulas used

Effective Odds (Win Commission)

\text{Eff} = 1 + (O - 1) \times (1 - c)

Effective Odds (Bet Commission)

\text{Eff} = O \times (1 - c)

Implied Probability Total (Arbitrage %)

\text{Arb} = \sum_{i=1}^{n} \frac{1}{\text{Eff}_i}

Profit Margin

\text{Margin} = (1 - \text{Arb}) \times 100\%

Guaranteed Return

R = \frac{\text{Total Stake}}{\text{Arb}}

Stake per Outcome

S_i = \frac{R}{\text{Eff}_i}

Guaranteed Profit

\text{Profit} = R - \text{Total Stake}

Return on Investment

\text{ROI} = \frac{\text{Profit}}{\text{Total Stake}} \times 100\%

Frequently asked questions

What does the implied probability total mean?

The implied probability total adds up the chance each outcome has based on the odds. If this number is below 100%, a surebet exists. If it is 100% or higher, there is no guaranteed profit. The lower the number, the bigger your profit margin.

What is the difference between 2-Way and 3-Way market types?

A 2-Way market has two possible outcomes, like a tennis match or an over/under bet. A 3-Way market has three possible outcomes, like a football match where the home team can win, the away team can win, or the game can end in a draw.

What does Fix This Stake do?

When you fix a stake on one outcome, the calculator treats that amount as locked. It then adjusts all the other stakes and the total stake to keep the surebet balanced. This is useful when a bookmaker has a maximum bet limit on one side.

What is the difference between Win and Bet commission types?

Win commission is taken only from your profit when your bet wins. Bet commission is taken from the full amount you wager, win or lose. Betting exchanges like Betfair typically use win commission.

Why do my profits change when I round the stakes?

Rounding adjusts each stake to a whole or simpler number. This means the stakes are no longer perfectly balanced, so the guaranteed return may differ slightly depending on which outcome wins. Use smaller rounding steps like 0.01 for the most accurate results.

Can I use odds from the same bookmaker?

You can, but surebets almost never appear at a single bookmaker. Bookmakers set their odds so the implied probabilities add up to well over 100%. Surebets usually require comparing odds from two or more different bookmakers.

What are effective odds?

Effective odds are your real odds after commission is removed. If your exchange charges 5% commission on winnings, your payout is lower than the listed odds suggest. The calculator uses effective odds in all its math so your results are accurate.

What does the ROI number mean?

ROI stands for return on investment. It shows your guaranteed profit as a percentage of your total stake. For example, an ROI of 3% on a $100 total stake means you earn $3 in guaranteed profit no matter which outcome wins.

How do I enter fractional odds correctly?

Type the numerator, a forward slash, then the denominator. For example, type 3/1 for three-to-one odds or 5/2 for five-to-two odds. The calculator converts them to decimal automatically.

How do I enter American odds correctly?

For a favorite, type a minus sign followed by the number, like -150. For an underdog, type a plus sign followed by the number, like +200. The calculator converts them to decimal odds behind the scenes.

What does the Include This Leg checkbox do?

Unchecking this box removes that outcome from the calculation without erasing the odds or other data you entered. This lets you quickly test different combinations to see if a surebet still exists without a specific leg.

Why does the calculator say no surebet is available?

This means the implied probability total is 100% or higher. The odds you entered do not create a gap big enough to guarantee a profit. Try finding better odds at different bookmakers or check if you entered the odds correctly.

Does changing the currency affect the calculation?

No. Changing the currency only changes the symbol displayed next to money values. It does not convert amounts between currencies. Enter your stake in the currency you plan to bet with.

What is a typical surebet profit margin?

Most surebets have a profit margin between 1% and 5% of your total stake. Margins above 5% are rare. The smaller the margin, the more important it is to account for commissions and stake rounding.

Can I use this calculator for live or in-play bets?

Yes, but you need to be very fast. Live odds change every few seconds. By the time you place all your bets, the odds may have shifted and the surebet may no longer exist. Always double-check the odds before confirming each bet.

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