Free calculator
Odds converter
Type a price in any format. The rest update as you go, along with the probability the price implies.
e.g. +150 or -200
includes your stake
profit relative to stake
percent, before removing the vig
Implied probability includes the sportsbook's margin. Two sides of a market will normally add up to more than 100 percent.
Comparing prices across books?
Converting by hand is fine for one price. BetSuite watches your sportsbooks and flags the moments they disagree enough to matter.
Download Free →The three formats, and why they exist
American odds are built around $100. A positive number is the profit on a $100 stake, so +150 wins $150. A negative number is what you must stake to win $100, so -200 means risking $200 for a $100 profit. It is the default across US sportsbooks.
Decimal odds are the cleanest to work with: multiply your stake by the number and you have your total return, stake included. 2.50 turns $100 into $250. This is standard in Europe, Canada and on exchanges, and it is what most arbitrage math runs on.
Fractional odds show profit against stake. 3/2 means three in profit for every two staked. Common in the UK and in horse racing, rarer elsewhere.
Common prices at a glance
| American | Decimal | Fractional | Implied |
|---|---|---|---|
| -200 | 1.50 | 1/2 | 66.67% |
| -110 | 1.91 | 10/11 | 52.38% |
| +100 | 2.00 | 1/1 | 50.00% |
| +150 | 2.50 | 3/2 | 40.00% |
| +250 | 3.50 | 5/2 | 28.57% |
Why implied probability is the number that matters
Format is presentation. Implied probability is the price. Once you convert every book to a probability, comparing them becomes trivial, and you can see the sportsbook's margin sitting on top.
Take a standard -110 on both sides of a market. Each implies 52.38 percent, and together they total 104.76 percent. That extra 4.76 percent is the vig. When two different books disagree enough that the total drops below 100 percent, both sides can be backed for the same return either way, which is what the arbitrage calculator works out. Our sportsbook comparisons cover where those gaps tend to open up.