-251 Odds Explained
- Decimal
- 1.40
- American
- -251
- Fractional
- 39/98
- Implied probability
- 71.51%
- Polymarket
- 72¢
- $100 wins
- 39.84
- The fraction shown is the closest simple fraction to the odds rounded to 3 decimals, not an exact match.
- American
- -251
- Fractional
- 39/98
- Implied probability
- 71.51%
- Polymarket
- 72¢
- Profit
- 39.84
- Total return
- 139.84
1.398 decimal, -251 American, 71.51% implied probability
-251 is an American price:
the minus sign marks a favourite, and the number is the stake needed to win 100
. Every other format describes the same chance: 1.40 decimal, 39/98 fractional, 71.51% implied probability, 72¢ on Polymarket.
What -251 pays
A 100 stake at -251 returns 139.84 in total: your 100 back plus 39.84 profit. To win exactly 100 you would stake 251.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 3.98 | 13.98 |
| 25 | 9.96 | 34.96 |
| 50 | 19.92 | 69.92 |
| 100 | 39.84 | 139.84 |
| 500 | 199.20 | 699.20 |
| 1,000 | 398.41 | 1,398.41 |
Break-even and long-run results
The implied probability of -251 is 71.51%, and that number is also the break-even win rate: win more often than 71.51% 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% | -30.1% |
| 55% | -23.1% |
| 60% | -16.1% |
| 65% | -9.1% |
| 72% | 0.7% |
-251 marks a clear favourite without being a lock: the implied chance is 71.51%, so the bookmaker expects this outcome roughly two times in three. Moneylines on the better team in an evenly scheduled league, the higher-ranked tennis player, or the "under" in a low-total game are typical places to see it.
The vig at -251
If both sides of a two-way market were priced at -251, the implied probabilities would add up to 43.02% above 100%. That excess is the overround, or vig; as a share of stakes it is a 30.08% 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.
-251 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -251 is worth 1.390 decimal (-256 American); at 5% it drops to 1.378 (-264). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.390 | -256 | 71.92% |
| 5% | 1.378 | -264 | 72.54% |
Same price in other formats
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does -251 mean in betting?
-251 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -251 the implied probability is 71.51% and a 100 stake returns 139.84.
What is -251 in decimal odds?
-251 converts to 1.398 in decimal odds (usually shown as 1.40). Decimal odds are the total return per unit staked, so multiply your stake by 1.398 to get the return.
What is -251 as a fraction?
-251 is 39/98 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 -251?
A 100 stake at -251 wins 39.84 in profit and returns 139.84 including the stake. To win exactly 100 you would stake 251.00.
What win rate do I need at -251?
The break-even win rate equals the implied probability, 71.51%. Winning more often than that at this price is profitable over the long run; winning less often loses money.