How to Convert Sports Betting Odds
This odds converter makes it easy to switch between decimal odds, American odds, and fractional odds. Many bookmakers support all three odds formats. Of course, in the US, American odds are the most common, while decimal odds dominate Europe and Asia.
Decimal Odds Explained
Decimal odds are the standard odds format in most countries, and the odds quote the potential payout should the bet win.
Example: If you wager €100 on 2.0 decimal odds and your bet wins, your total payout is €200 (2.0 × €100 = €200). This payout includes your initial stake, so you need to subtract your initial stake (€100) to determine your profit: €200 - €100 = €100 profit.
As you can see in the odds converter, 2.0 is equivalent to +100 American odds and 1/1 fractional odds.
American Odds Explained
American odds are the main odds format in the US. Positive figures (e.g. +200, +450) represent total profit should the bet win, assuming the bet size is €100.
In other words, betting €100 at +200 odds means that you profit €200 if your bet wins.
Negative figures (e.g. -200, -450) represent how much a bettor must wager to win €100 profit. In other words, if a wager is -200 odds, a bettor must place €200 to earn €100 profit.
As shown in the odds converter, -200 American odds is equivalent to 1.50 decimal odds and 1/2 fractional odds.
Fractional Odds Explained
Fractional odds are mainly used in the UK, as well as Ireland. This odds format shows the potential profit should the bet win, quoted as a fraction of the stake.
Example: If you bet €100 on 1/2 (or 0.5) fractional odds and your bet wins, you will earn €50 profit (1/2 × €100).
As shown in the odds converter, 1/2 is equivalent to -200 American odds and 1.50 decimal odds.
Breakeven Win Probability
The odds converter also calculates the breakeven win probability of given odds, which can be very useful when evaluating a bet.
Example 1: If you place a bet at +100 odds (2.00 decimal), then the breakeven win probability is 50%. You should only place this wager if you believe the "true" or "fair" probability of the wager winning is greater than 50%.
Example 2: If you place a bet at +900 odds (10.00 decimal), then the breakeven win probability is only 10%. You only need to win +900 wagers 1/10 times to break even.
So if you evaluate a bet as having a 12.5% chance of winning, then this bet is mathematically profitable when the odds offer 10% breakeven. The "true" odds are greater than the breakeven threshold.
How to Use the Odds Converter
- Enter odds in any format (Fractional, Decimal, American, or Probability %)
- The calculator automatically converts to all other formats
- See breakeven probability to evaluate if the bet offers value
- Compare to fair probability from sharp books to find +EV bets
Using Odds Converter for Value Betting
This odds converter helps you understand what odds mean across different formats. To find value bets, combine this with:
- No-Vig Calculator to find fair odds
- Expected Value Calculator to calculate profit
- Hold Calculator to find low-vig markets
Or use FairOdds Terminal which does all calculations automatically across 60+ bookmakers.
Start your free trial for automated odds comparison and value bet detection.
Odds Converter FAQ
What does an odds converter do?
Odds converters change odds between decimal, fractional, and American formats. Decimal (2.00) is standard globally, fractional (1/1) is popular in UK/Ireland, and American (+100/-100) is used in the United States. The converter also calculates breakeven win probability.
How do you convert odds?
Enter odds in any format and the calculator automatically converts to all other formats. Decimal 2.0 = American +100 = Fractional 1/1 = 50% probability. The converter handles the math instantly for all three formats.
What are decimal odds?
Decimal odds (e.g., 2.10) show total payout including stake. €100 at 2.10 odds = €210 total payout (€110 profit + €100 stake). Decimal is the standard format in Europe, Asia, and most of the world.
What are American odds?
American odds use + and - signs. Positive (+200) shows profit on €100 bet. Negative (-200) shows amount needed to win €100 profit. Common in US sportsbooks like DraftKings, FanDuel.
What are fractional odds?
Fractional odds (e.g., 11/10 or 1/2) show profit as fraction of stake. €100 on 1/2 odds = €50 profit. Popular in UK and Ireland betting markets. Fractional 1/1 = Decimal 2.00 = American +100.
What is breakeven probability?
Breakeven probability is the win rate needed to break even at given odds. At 2.00 odds (50% probability), you need to win 50% of the time. At 3.00 odds (33.3% probability), you only need to win 1 in 3 bets to break even.