+309 Odds Explained
- Decimal
- 4.09
- American
- +309
- Fractional
- 309/100
- Implied probability
- 24.45%
- Polymarket
- 24¢
- $100 wins
- 309.00
- American
- +309
- Fractional
- 309/100
- Implied probability
- 24.45%
- Polymarket
- 24¢
- Profit
- 309.00
- Total return
- 409.00
4.090 decimal, +309 American, 24.45% implied probability
The price +309 converts to 4.09 decimal odds and 309/100 fractional odds. Read as a probability it says the bookmaker prices this outcome at 24.45%, 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 24¢.
What +309 pays
A 100 stake at +309 returns 409.00 in total: your 100 back plus 309.00 profit. To win exactly 100 you would stake 32.36. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 30.90 | 40.90 |
| 25 | 77.25 | 102.25 |
| 50 | 154.50 | 204.50 |
| 100 | 309.00 | 409.00 |
| 500 | 1,545.00 | 2,045.00 |
| 1,000 | 3,090.00 | 4,090.00 |
Break-even and long-run results
The implied probability of +309 is 24.45%, and that number is also the break-even win rate: win more often than 24.45% 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 |
|---|---|
| 24% | -1.8% |
| 50% | 104.5% |
| 55% | 125.0% |
| 60% | 145.4% |
| 65% | 165.9% |
With an implied chance of 24.45%, a bet at +309 is expected to lose most of the time and to pay 309.00 on 100 when it does not. Outright markets, correct scores and big upsets are where these prices appear, and they are the prices bookmakers shade the hardest.
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 -104.50% 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 4.028 decimal (+303 American); at 5% it drops to 3.935 (+294). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 4.028 | +303 | 24.82% |
| 5% | 3.935 | +294 | 25.41% |
Same price in other formats
Nearby prices
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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 24.45% and a 100 stake returns 409.00.
What is +309 in decimal odds?
+309 converts to 4.090 in decimal odds (usually shown as 4.09). Decimal odds are the total return per unit staked, so multiply your stake by 4.090 to get the return.
What is +309 as a fraction?
+309 is 309/100 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 309.00 in profit and returns 409.00 including the stake. To win exactly 100 you would stake 32.36.
What win rate do I need at +309?
The break-even win rate equals the implied probability, 24.45%. Winning more often than that at this price is profitable over the long run; winning less often loses money.