-320 Odds Explained
- Decimal
- 1.31
- American
- -320
- Fractional
- 5/16
- Implied probability
- 76.19%
- Polymarket
- 76¢
- $100 wins
- 31.25
- American
- -320
- Fractional
- 5/16
- Implied probability
- 76.19%
- Polymarket
- 76¢
- Profit
- 31.25
- Total return
- 131.25
1.313 decimal, -320 American, 76.19% implied probability
The price -320 converts to 1.31 decimal odds and 5/16 fractional odds. Read as a probability it says the bookmaker prices this outcome at 76.19%, which is the share of the time you would need to win just to break even. A prediction market would quote the same chance as 76¢.
What -320 pays
A 100 stake at -320 returns 131.25 in total: your 100 back plus 31.25 profit. To win exactly 100 you would stake 320.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 3.13 | 13.13 |
| 25 | 7.81 | 32.81 |
| 50 | 15.63 | 65.63 |
| 100 | 31.25 | 131.25 |
| 500 | 156.25 | 656.25 |
| 1,000 | 312.50 | 1,312.50 |
Break-even and long-run results
The implied probability of -320 is 76.19%, and that number is also the break-even win rate: win more often than 76.19% of the time at this price and you profit in the long run, win less often and you lose. The table shows the return on stake at a few win rates, including the break-even rate itself.
| Win rate | Return on stake |
|---|---|
| 50% | -34.4% |
| 55% | -27.8% |
| 60% | -21.3% |
| 65% | -14.7% |
| 76% | -0.3% |
At 76.19% this is a heavy favourite. Prices this short appear when one side is expected to win comfortably: a top seed against a qualifier, a strong home team against a relegation candidate, or a moneyline in a game with a double-digit spread. The catch is the payout. You need to win more than 76.19% of these bets just to stand still, and one loss wipes out several wins.
The vig at -320
If both sides of a two-way market were priced at -320, the implied probabilities would add up to 52.38% above 100%. That excess is the overround, or vig; as a share of stakes it is a 34.38% margin for the bookmaker. Removing it leaves fair odds of 2.00 decimal ( +100) on each side. Use the devig calculator to do the same for any market.
-320 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -320 is worth 1.306 decimal (-327 American); at 5% it drops to 1.297 (-337). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.306 | -327 | 76.56% |
| 5% | 1.297 | -337 | 77.11% |
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does -320 mean in betting?
-320 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -320 the implied probability is 76.19% and a 100 stake returns 131.25.
What is -320 in decimal odds?
-320 converts to 1.313 in decimal odds (usually shown as 1.31). Decimal odds are the total return per unit staked, so multiply your stake by 1.313 to get the return.
What is -320 as a fraction?
-320 is 5/16 in fractional odds, the traditional bookmaker notation where the top number is profit and the bottom number is stake.
How much do I win on a 100 bet at -320?
A 100 stake at -320 wins 31.25 in profit and returns 131.25 including the stake. To win exactly 100 you would stake 320.00.
What win rate do I need at -320?
The break-even win rate equals the implied probability, 76.19%. Winning more often than that at this price is profitable over the long run; winning less often loses money.