Read the price in the format you use
Decimal 2.50, American +150 and fractional 3/2 describe the same price. The implied probability is 40%. This is the break-even percentage implied by that price, not an independently assessed probability of the outcome.
Fractional outputs are approximate where a decimal needs a longer fraction. American outputs are rounded to the nearest whole number.
Visualise the price-implied probability
Move the decimal price to see its implied probability and a C$20 winning cash-bet return.
- Winning return
- C$50.00
- Profit after stake
- C$30.00
- If the bet loses
- −C$20.00
Illustrative prices, not live odds. Formula: 100 ÷ decimal odds. This is a break-even price calculation, not a forecast or a measured chance of winning.
A market can include a bookmaker margin
Adding the implied probabilities for every mutually exclusive result can produce a total above 100%. Compare complete and equivalent markets if you want to assess that difference.
A better number is only comparable when the event and settlement conditions match. A sack counted as a run at one sportsbook and a pass at another changes the underlying football selection.