Arbitrage Calculator — Surebet & Arb Betting Calculator | AgentBets.ai

Enter odds from different sportsbooks to instantly detect arbitrage opportunities. The calculator shows optimal stake splits for guaranteed profit and accounts for platform fees.

Odds Format

American Decimal Fractional

Outcomes

Sportsbook Outcome Odds Impl. Prob

Total Stake ($)

Fee / Commission (%)

How the Arbitrage Calculator Works

Step 1: Convert to Implied Probability

Every odds value represents a bookmaker’s implied probability for that outcome. The first step is to convert all odds — regardless of format — into implied probabilities.

Format	Formula	Example	Implied Prob
American +	100 / (odds + 100)	+150	40.0%
American −	\|odds\| / (\|odds\| + 100)	−130	56.5%
Decimal	1 / odds	2.50	40.0%
Fractional	denominator / (numerator + denominator)	3/2	40.0%

Step 2: Check for Arbitrage

Add the implied probabilities from the best available odds per outcome across different books. If the total is less than 100%, an arbitrage opportunity exists.

Example: Team A at +150 on DraftKings (40.0%) and Team B at +110 on FanDuel (47.6%). Total: 87.6% — that’s a 12.4% gap below 100%, meaning a guaranteed profit exists.

Step 3: Calculate Optimal Stakes

For equal profit across all outcomes, the stake on each outcome is proportional to its implied probability:

stake_i = total_stake × (implied_i / sum_of_all_implieds)

This ensures that no matter which outcome wins, you receive the same payout.

Step 4: Account for Fees

Platform fees reduce your actual payout. The calculator applies a flat fee percentage to all payouts. In practice, fees vary:

Polymarket: ~2% on net winnings
Kalshi: 0% on contract payouts (fee built into spread)
Sportsbooks: 4–10% vig built into odds (already reflected in the odds you enter)

What Is a Good Arb Percentage?

Arb %	Assessment
0.5–1.5%	Typical. Common in liquid sports markets. Thin margin — fees can erase it.
1.5–3.0%	Good. Worth pursuing if execution is fast.
3.0–5.0%	Strong. Usually appears around line movements or cross-market pricing.
5.0%+	Rare. Verify the odds are correct — may indicate a stale line or error.

Most sustainable arb operations target the 1–3% range and rely on volume for profit. The Sports Betting Arbitrage Bot Guide covers how to automate the full detection-to-execution pipeline.

Try It with Live Odds

This calculator works with any odds you type in, but finding real arbs manually means checking dozens of sportsbooks for every event. TheOddsPulse delivers real-time odds from 10+ sportsbooks through a single API, making it easy to feed live data into your arb detection pipeline.