arbitrage calculator

Use this free arbitrage calculator to test whether a set of betting odds creates a true surebet. Enter your total stake, add at least two outcomes, and the calculator will split your stake across outcomes to show whether a guaranteed profit exists.

What Is Arbitrage Betting?

Arbitrage betting (often called a surebet) is when you place bets on all possible outcomes of the same event at different prices, so that no matter what happens, you lock in a profit. This works when the combined implied probabilities are less than 100%.

The key formula is simple:

• Implied probability for an outcome = 1 / decimal odds
• Total implied probability = sum of all implied probabilities
• If the total is below 1.00 (or 100%), an arbitrage opportunity exists.

How This Arbitrage Calculator Works

This tool does two main jobs:

• Checks whether your odds create a real arbitrage opportunity.
• Calculates the exact stake split for each outcome so payouts are nearly equal.

Stake sizing is done proportionally using inverse odds, which is the standard method most professional bettors use when they want a balanced guaranteed return.

Inputs You Should Prepare

• Total stake amount you want to commit.
• Best available odds for each possible result.
• Optional third outcome for 3-way markets (e.g., soccer home/draw/away).

Step-by-Step Example

Suppose you find a two-way market with decimal odds of 2.10 and 2.05 at different sportsbooks. The implied probabilities are approximately 47.62% and 48.78%, which sum to 96.40%. Because this is below 100%, the market has arbitrage room.

If you invest $100 total, the calculator allocates your stake between both sides so each winning path returns almost the same payout. The difference between that payout and your total stake is your guaranteed profit before fees, limits, or account restrictions.

Common Mistakes to Avoid

1) Ignoring Odds Movement

Odds can change in seconds. Always confirm both bets are accepted at the expected price before assuming profit is locked in.

2) Forgetting Commissions and Rules

Some exchanges charge commission, and some books have special market rules (voids, overtime rules, dead heat, etc.). Small rule differences can turn a “risk-free” setup into real risk.

3) Rounding Stakes Too Aggressively

If you round heavily, your “equal payout” balance can drift enough to remove profit. Use cents precision whenever possible.

Risk Management Notes

• Use trusted sportsbooks with clear payout history.
• Track all bets in a spreadsheet: stake, odds, timestamp, and expected profit.
• Start small until you are comfortable with execution speed.
• Never risk money you cannot afford to lose—operational errors do happen.

Frequently Asked Questions

Is arbitrage betting legal?

Legality depends on your country or state. Check local gambling laws and platform terms before placing any bets.

Can sportsbooks limit arbitrage bettors?

Yes. Many operators monitor patterns and may reduce limits or restrict accounts. This is one of the biggest practical constraints in long-term arbitrage betting.

Does this calculator guarantee real-world profit?

It guarantees the math, not execution. Real-world profit depends on successful placement, unchanged odds, matching market rules, and no settlement disputes.