Free betting tool
Convert both sides of an American-odds market into implied probabilities, sportsbook margin, and fair no-vig odds.
Two-way market
Use American odds from the same sportsbook and market. The calculator removes the book's margin by normalizing both implied probabilities.
Sportsbook margin
4.76%
A negative number can indicate an arbitrage opportunity before limits and execution costs.
American odds imply a break-even probability. At -110, that probability is 52.38%. Two sides at -110 add to 104.76%, so the extra 4.76% is the sportsbook's hold.
The no-vig calculation divides each side's implied probability by their combined total. For a balanced -110/-110 market, both fair probabilities become 50% and both fair prices become +100.
Removing the vig does not predict who will win. It only estimates the market's fair split before the bookmaker margin. Compare that baseline with injury context, prices, and your own probability estimate.