Arbitrage calculator

Enter the best price available on each outcome and a total stake. The calculator splits the stake so that every outcome returns the same amount, and tells you whether that return beats what you put in.

Outcome 1 priceOutcome 2 price

Total stake

Arbitrage — guaranteed profit

+37.35

3.73% of stake, whichever outcome wins. The prices imply 96.40% in total — less than a whole event.

Outcome	Price	Stake	Returns	Profit
Outcome 1	2.100	493.98	1,037.35	+37.35
Outcome 2	2.050	506.02	1,037.35	+37.35

Stakes are split in proportion to each price's implied probability, which is what makes every return identical.

Common questions

When does an arbitrage exist?: When the implied probabilities of every outcome add up to LESS than 100%. The prices then describe less than a whole event, so buying all of it costs less than it pays out. A total above 100% is the ordinary case — the excess is the bookmaker's margin, and no split of stakes can turn that into a profit.
How do you calculate arbitrage stakes?: Each stake is proportional to its outcome's implied probability: the total stake multiplied by one divided by that price, divided by the sum of one-over-each-price. That is exactly what makes every return identical.
Why do arbitrages disappear so quickly?: Prices move, and the side you were counting on shortens as soon as money arrives on it. Arbitrages are usually small, brief, and limited by how much a book will accept.

Arbitrage calculator

Outcome 1 priceOutcome 2 price

Total stake

Arbitrage — guaranteed profit

+37.35

3.73% of stake, whichever outcome wins. The prices imply 96.40% in total — less than a whole event.

Outcome	Price	Stake	Returns	Profit
Outcome 1	2.100	493.98	1,037.35	+37.35
Outcome 2	2.050	506.02	1,037.35	+37.35

Stakes are split in proportion to each price's implied probability, which is what makes every return identical.

Common questions

When does an arbitrage exist?

When the implied probabilities of every outcome add up to LESS than 100%. The prices then describe less than a whole event, so buying all of it costs less than it pays out. A total above 100% is the ordinary case — the excess is the bookmaker's margin, and no split of stakes can turn that into a profit.

How do you calculate arbitrage stakes?

Each stake is proportional to its outcome's implied probability: the total stake multiplied by one divided by that price, divided by the sum of one-over-each-price. That is exactly what makes every return identical.

Why do arbitrages disappear so quickly?

Prices move, and the side you were counting on shortens as soon as money arrives on it. Arbitrages are usually small, brief, and limited by how much a book will accept.