-171 Odds Explained
- Decimal
- 1.58
- American
- -171
- Fractional
- 31/53
- Implied probability
- 63.10%
- Polymarket
- 63¢
- $100 wins
- 58.48
- The fraction shown is the closest simple fraction to the odds rounded to 3 decimals, not an exact match.
- American
- -171
- Fractional
- 31/53
- Implied probability
- 63.10%
- Polymarket
- 63¢
- Profit
- 58.48
- Total return
- 158.48
1.585 decimal, -171 American, 63.10% implied probability
The price -171 converts to 1.58 decimal odds and 31/53 fractional odds. Read as a probability it says the bookmaker prices this outcome at 63.10%, 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 63¢.
What -171 pays
A 100 stake at -171 returns 158.48 in total: your 100 back plus 58.48 profit. To win exactly 100 you would stake 171.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 5.85 | 15.85 |
| 25 | 14.62 | 39.62 |
| 50 | 29.24 | 79.24 |
| 100 | 58.48 | 158.48 |
| 500 | 292.40 | 792.40 |
| 1,000 | 584.80 | 1,584.80 |
Break-even and long-run results
The implied probability of -171 is 63.10%, and that number is also the break-even win rate: win more often than 63.10% 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% | -20.8% |
| 55% | -12.8% |
| 60% | -4.9% |
| 63% | -0.2% |
| 65% | 3.0% |
With an implied probability of 63.10%, -171 is a moderate favourite. Prices in this band are where the bookmaker's margin is easiest to see: the opposite side of the market is usually priced a little longer than the fair line, and the two implied probabilities add up to more than 100%.
The vig at -171
If both sides of a two-way market were priced at -171, the implied probabilities would add up to 26.20% above 100%. That excess is the overround, or vig; as a share of stakes it is a 20.76% 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.
-171 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -171 is worth 1.573 decimal (-174 American); at 5% it drops to 1.556 (-180). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.573 | -174 | 63.57% |
| 5% | 1.556 | -180 | 64.29% |
Same price in other formats
Nearby prices
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Frequently asked questions
What does -171 mean in betting?
-171 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -171 the implied probability is 63.10% and a 100 stake returns 158.48.
What is -171 in decimal odds?
-171 converts to 1.585 in decimal odds (usually shown as 1.58). Decimal odds are the total return per unit staked, so multiply your stake by 1.585 to get the return.
What is -171 as a fraction?
-171 is 31/53 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 -171?
A 100 stake at -171 wins 58.48 in profit and returns 158.48 including the stake. To win exactly 100 you would stake 171.00.
What win rate do I need at -171?
The break-even win rate equals the implied probability, 63.10%. Winning more often than that at this price is profitable over the long run; winning less often loses money.