-309 Odds Explained
- Decimal
- 1.32
- American
- -309
- Fractional
- 11/34
- Implied probability
- 75.55%
- Polymarket
- 76¢
- $100 wins
- 32.36
- The fraction shown is the closest simple fraction to the odds rounded to 3 decimals, not an exact match.
- American
- -309
- Fractional
- 11/34
- Implied probability
- 75.55%
- Polymarket
- 76¢
- Profit
- 32.36
- Total return
- 132.36
1.324 decimal, -309 American, 75.55% implied probability
American odds of -309 mean
you risk 309 to win 100
. In decimal notation that is 1.32, in fractional notation 11/34, and the implied probability is 75.55%. On a prediction market the same price is a 76¢ share.
What -309 pays
A 100 stake at -309 returns 132.36 in total: your 100 back plus 32.36 profit. To win exactly 100 you would stake 309.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 3.24 | 13.24 |
| 25 | 8.09 | 33.09 |
| 50 | 16.18 | 66.18 |
| 100 | 32.36 | 132.36 |
| 500 | 161.81 | 661.81 |
| 1,000 | 323.62 | 1,323.62 |
Break-even and long-run results
The implied probability of -309 is 75.55%, and that number is also the break-even win rate: win more often than 75.55% 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% | -33.8% |
| 55% | -27.2% |
| 60% | -20.6% |
| 65% | -14.0% |
| 76% | 0.6% |
A price of -309 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 -309
If both sides of a two-way market were priced at -309, the implied probabilities would add up to 51.10% above 100%. That excess is the overround, or vig; as a share of stakes it is a 33.82% 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.
-309 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -309 is worth 1.317 decimal (-315 American); at 5% it drops to 1.307 (-325). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.317 | -315 | 75.92% |
| 5% | 1.307 | -325 | 76.49% |
Same price in other formats
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does -309 mean in betting?
-309 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -309 the implied probability is 75.55% and a 100 stake returns 132.36.
What is -309 in decimal odds?
-309 converts to 1.324 in decimal odds (usually shown as 1.32). Decimal odds are the total return per unit staked, so multiply your stake by 1.324 to get the return.
What is -309 as a fraction?
-309 is 11/34 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 -309?
A 100 stake at -309 wins 32.36 in profit and returns 132.36 including the stake. To win exactly 100 you would stake 309.00.
What win rate do I need at -309?
The break-even win rate equals the implied probability, 75.55%. Winning more often than that at this price is profitable over the long run; winning less often loses money.