+331 Odds Explained
- Decimal
- 4.31
- American
- +331
- Fractional
- 331/100
- Implied probability
- 23.20%
- Polymarket
- 23¢
- $100 wins
- 331.00
- American
- +331
- Fractional
- 331/100
- Implied probability
- 23.20%
- Polymarket
- 23¢
- Profit
- 331.00
- Total return
- 431.00
4.310 decimal, +331 American, 23.20% implied probability
+331 is an American price:
the plus sign marks an underdog, and the number is the profit on a 100 stake
. Every other format describes the same chance: 4.31 decimal, 331/100 fractional, 23.20% implied probability, 23¢ on Polymarket.
What +331 pays
A 100 stake at +331 returns 431.00 in total: your 100 back plus 331.00 profit. To win exactly 100 you would stake 30.21. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 33.10 | 43.10 |
| 25 | 82.75 | 107.75 |
| 50 | 165.50 | 215.50 |
| 100 | 331.00 | 431.00 |
| 500 | 1,655.00 | 2,155.00 |
| 1,000 | 3,310.00 | 4,310.00 |
Break-even and long-run results
The implied probability of +331 is 23.20%, and that number is also the break-even win rate: win more often than 23.20% 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 |
|---|---|
| 23% | -0.9% |
| 50% | 115.5% |
| 55% | 137.1% |
| 60% | 158.6% |
| 65% | 180.2% |
+331 is a longshot. The bookmaker prices the outcome at 23.20%, and the payout of 331.00 per 100 staked is the compensation for how rarely it lands. Longshots carry more margin than any other part of the market, which is why devigging methods disagree most at prices like this one.
The vig at +331
If both sides of a two-way market were priced at +331, the implied probabilities would add up to -53.60% above 100%. That excess is the overround, or vig; as a share of stakes it is a -115.50% 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.
+331 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission +331 is worth 4.244 decimal (+324 American); at 5% it drops to 4.145 (+314). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 4.244 | +324 | 23.56% |
| 5% | 4.145 | +314 | 24.13% |
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does +331 mean in betting?
+331 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At +331 the implied probability is 23.20% and a 100 stake returns 431.00.
What is +331 in decimal odds?
+331 converts to 4.310 in decimal odds (usually shown as 4.31). Decimal odds are the total return per unit staked, so multiply your stake by 4.310 to get the return.
What is +331 as a fraction?
+331 is 331/100 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 +331?
A 100 stake at +331 wins 331.00 in profit and returns 431.00 including the stake. To win exactly 100 you would stake 30.21.
What win rate do I need at +331?
The break-even win rate equals the implied probability, 23.20%. Winning more often than that at this price is profitable over the long run; winning less often loses money.