Arbitrage betting calculator
Enter the odds for each outcome. The calculator tells you whether it's an arbitrage, how much to stake on each side, and the profit you lock in. It handles 2-way and 3-way markets, every odds format, exchange commission, lay bets, and free bets.
Outcomes (2-way)
- Outcome 1SelectionSportsbook
OddsStake$2.12 · 28/25 · 47.17% · Returns $104.98
- Outcome 2SelectionSportsbook
OddsStake$2.08 · 27/25 · 48.08% · Returns $105.00
Result
Guaranteed profit $4.98
4.98% return on $100.00. You get this back whichever outcome wins.
- Total stake
- $100.00
- Profit
- $4.98
- ROI
- 4.98%
- Market total
- 95.25%
| If this wins | Bet | Profit |
|---|---|---|
| LakersFanDuel | $49.52 | +$4.98 |
| CelticsDraftKings | $50.48 | +$5.00 |
Break-even odds
How far each price can move, with the others unchanged, before the edge is gone.
- Lakers≥ -108
- Celtics≥ -112
How to use the arbitrage calculator
- 1
Pick the odds format
Choose American, decimal, fractional, or implied %. Odds you've already typed convert automatically. - 2
Enter each outcome's best price
Add one row per outcome. Use the best price you can find for each one, even if they're at different sportsbooks. - 3
Set your stake
Type a total stake, or lock one leg's stake (for example a book's maximum bet) and the calculator sizes the others from it. - 4
Read the result and place the bets
If the market total is under 100%, the calculator shows the stake for each leg and the profit you lock in. Place every leg before the odds move.
What each setting does
| Setting | What it does |
|---|---|
| Odds format | American (+150), decimal (2.50), fractional (3/2), or implied probability (40%). Switching converts what you've typed. |
| Total stake | The combined amount across every leg. The calculator splits it so each outcome pays the same. |
| Lock a stake | Fix one leg's stake and size the rest from it. Handy for max bets and free bets. |
| Round stakes | Exact, nearest $1, prefer $5, one leg $5, all legs $5, or a custom step. It picks the rounded stakes that cost the least profit. |
| Profit split | Same profit on every outcome, or all of it on one outcome while you break even on the rest. |
| Commission | The exchange's cut of net winnings, in percent. Applied per leg. |
| Lay bet | A bet that an outcome won't happen. You enter the lay odds; the calculator gives the lay stake and your liability. |
| Free bet | The stake isn't returned and costs you no cash. The result shows how much of the free bet you keep. |
| Manual stakes | Type every stake yourself and see what each outcome pays. Nothing gets re-sized. |
| Days until it settles | Turns the return into an annualized rate, which matters for futures that tie up money for months. |
The formulas behind it
Everything starts from decimal odds. American +112 is 2.12 in decimal, and -120 is 1.833.
Implied probability
implied probability = 1 ÷ decimal odds
Market total
market total = sum of every outcome's implied probability
Stake on each outcome
stake = total stake × implied probability ÷ market total
Guaranteed return
return = total stake ÷ market total
With commission c
effective odds = 1 + (decimal odds − 1) × (1 − c)
Lay liability
liability = lay stake × (lay odds − 1)
For a full walk-through with a worked example, read how to calculate arbitrage bets.
Reading the result
- Market total is the sum of the implied probabilities. Under 100% is an arbitrage. A total of 97% means about a 3% return.
- Profit and ROI are the worst case across every outcome, after rounding and commission.
- Break-even odds show how far each price can drop before the edge is gone. If a line moves while you're placing the bets, check it here.
- Odds you'd need replaces break-even when there's no arbitrage. It tells you the price to wait for on each outcome.
- Rounding cost is how much worst-case profit you give up compared with exact stakes.
Find the odds to put in the calculator
Arbocado's Arbitrage Finder scans every major sportsbook and exchange for live sure bets and sizes each leg for you. The Pro desktop app fills the bet slips; you confirm every bet.
Open the Arbitrage FinderFrequently asked questions
How does an arbitrage calculator work?
It converts each outcome's odds to an implied probability and adds them up. If the total is under 100%, the odds are an arbitrage. It then splits your stake in proportion to those probabilities so every outcome pays back the same amount, which locks in the profit.
How do I calculate arbitrage stakes?
Each outcome's stake is your total stake times its implied probability, divided by the sum of all implied probabilities. On $100 with +112 and +108, that's $49.52 and $50.48, and either result returns about $104.99.
Can I use this calculator for three-way markets like soccer?
Yes. Click 3-way or add outcomes up to six. A three-way market such as home, draw, and away is an arbitrage when the three implied probabilities add up to under 100%.
How do exchange commission and lay bets affect the math?
Commission is taken from net winnings, so a 2% to 5% fee lowers the effective odds on that leg and can turn a thin arbitrage into a loss. A lay bet pays when an outcome loses, and your liability is the lay stake times the lay odds minus one. Turn on advanced options to enter both.
Should I round my arbitrage stakes?
Rounding stakes to multiples of $5 makes bets look less like they came from a calculator, which helps avoid account limits. It costs a little profit, and the calculator shows how much. On small stakes or thin edges, rounding can erase the profit entirely.