How to use this calculator
Type any odds value into the input field. The format is detected automatically — you can also select it manually from the dropdown. Set your stake to see exact profit and total return figures.
Use this tool to compare lines across sportsbooks that display different formats, or to quickly check the implied probability before placing a bet.
Formulas
American (+) to implied prob: 100 / (odds + 100)
American (-) to implied prob: |odds| / (|odds| + 100)
Decimal to implied prob: 1 / decimal
Fractional (n/d) to decimal: (n / d) + 1
Profit on stake S at decimal D: S x (D - 1)
Examples
+150 (American underdog): Implied probability = 100 / (150 + 100) = 40.0%. Decimal = 2.50. Fractional = 3/2. A $100 bet profits $150.
-110 (standard spread price): Implied probability = 110 / (110 + 100) = 52.38%. Decimal = 1.909. Fractional = 10/11. A $110 bet profits $100.
Frequently asked questions
What does +150 mean in betting?
+150 means you profit $150 on a $100 bet. The implied probability is 40%. Any positive American line means the team is an underdog. The higher the number, the bigger the underdog.
How do I convert -110 to implied probability?
For negative American odds use: |odds| / (|odds| + 100). For -110 that is 110 / 210 = 52.38%. This is the break-even win rate you need at this price to profit long-term.
What is vig (juice)?
Vig is the sportsbook's built-in commission. On a standard -110 / -110 line, both sides imply 52.38%, which adds up to 104.76% total. The extra 4.76% is the vig — it is why you need to win more than 50% of your bets to break even.
What is decimal odds format?
Decimal odds show your total return per $1 staked, including your stake back. So 2.50 decimal returns $250 on a $100 bet ($150 profit + $100 stake). Common in Europe and Australia.
