-321 Odds Explained
- Decimal
- 1.31
- American
- -321
- Fractional
- 19/61
- Implied probability
- 76.25%
- Polymarket
- 76¢
- $100 wins
- 31.15
- The fraction shown is the closest simple fraction to the odds rounded to 3 decimals, not an exact match.
- American
- -321
- Fractional
- 19/61
- Implied probability
- 76.25%
- Polymarket
- 76¢
- Profit
- 31.15
- Total return
- 131.15
1.312 decimal, -321 American, 76.25% implied probability
The price -321 converts to 1.31 decimal odds and 19/61 fractional odds. Read as a probability it says the bookmaker prices this outcome at 76.25%, 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 -321 pays
A 100 stake at -321 returns 131.15 in total: your 100 back plus 31.15 profit. To win exactly 100 you would stake 321.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 3.12 | 13.12 |
| 25 | 7.79 | 32.79 |
| 50 | 15.58 | 65.58 |
| 100 | 31.15 | 131.15 |
| 500 | 155.76 | 655.76 |
| 1,000 | 311.53 | 1,311.53 |
Break-even and long-run results
The implied probability of -321 is 76.25%, and that number is also the break-even win rate: win more often than 76.25% 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% | -27.9% |
| 60% | -21.3% |
| 65% | -14.8% |
| 76% | -0.3% |
A price of -321 is deep odds-on. Bookmakers quote it when an outcome is close to a formality, and the margin they take is proportionally large at this end of the market. Sharp bettors tend to look at the other side of such a market, or at the exchange, where the same favourite is often available a tick or two better.
The vig at -321
If both sides of a two-way market were priced at -321, the implied probabilities would add up to 52.49% above 100%. That excess is the overround, or vig; as a share of stakes it is a 34.42% 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.
-321 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -321 is worth 1.305 decimal (-328 American); at 5% it drops to 1.296 (-338). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.305 | -328 | 76.61% |
| 5% | 1.296 | -338 | 77.16% |
Same price in other formats
Nearby prices
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Frequently asked questions
What does -321 mean in betting?
-321 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -321 the implied probability is 76.25% and a 100 stake returns 131.15.
What is -321 in decimal odds?
-321 converts to 1.312 in decimal odds (usually shown as 1.31). Decimal odds are the total return per unit staked, so multiply your stake by 1.312 to get the return.
What is -321 as a fraction?
-321 is 19/61 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 -321?
A 100 stake at -321 wins 31.15 in profit and returns 131.15 including the stake. To win exactly 100 you would stake 321.00.
What win rate do I need at -321?
The break-even win rate equals the implied probability, 76.25%. Winning more often than that at this price is profitable over the long run; winning less often loses money.