-101 Odds Explained
- Decimal
- 1.99
- American
- -101
- Fractional
- 99/100
- Implied probability
- 50.25%
- Polymarket
- 50¢
- $100 wins
- 99.01
- The fraction shown is the closest simple fraction to the odds rounded to 3 decimals, not an exact match.
- American
- -101
- Fractional
- 99/100
- Implied probability
- 50.25%
- Polymarket
- 50¢
- Profit
- 99.01
- Total return
- 199.01
1.990 decimal, -101 American, 50.25% implied probability
American odds of -101 mean
you risk 101 to win 100
. In decimal notation that is 1.99, in fractional notation 99/100, and the implied probability is 50.25%. On a prediction market the same price is a 50¢ share.
What -101 pays
A 100 stake at -101 returns 199.01 in total: your 100 back plus 99.01 profit. To win exactly 100 you would stake 101.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 9.90 | 19.90 |
| 25 | 24.75 | 49.75 |
| 50 | 49.50 | 99.50 |
| 100 | 99.01 | 199.01 |
| 500 | 495.05 | 995.05 |
| 1,000 | 990.10 | 1,990.10 |
Break-even and long-run results
The implied probability of -101 is 50.25%, and that number is also the break-even win rate: win more often than 50.25% 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% | -0.5% |
| 55% | 9.5% |
| 60% | 19.4% |
| 65% | 29.4% |
-101 sits close to even money. The bookmaker sees this as roughly a coin flip, with the margin nudging both sides of the market a little under fair. Point spreads and totals live here: the line moves to make each side about a 50% proposition, and the price carries the juice.
The vig at -101
If both sides of a two-way market were priced at -101, the implied probabilities would add up to 0.50% above 100%. That excess is the overround, or vig; as a share of stakes it is a 0.50% 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.
-101 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -101 is worth 1.970 decimal (-103 American); at 5% it drops to 1.941 (-106). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.970 | -103 | 50.75% |
| 5% | 1.941 | -106 | 51.53% |
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does -101 mean in betting?
-101 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -101 the implied probability is 50.25% and a 100 stake returns 199.01.
What is -101 in decimal odds?
-101 converts to 1.990 in decimal odds (usually shown as 1.99). Decimal odds are the total return per unit staked, so multiply your stake by 1.990 to get the return.
What is -101 as a fraction?
-101 is 99/100 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 -101?
A 100 stake at -101 wins 99.01 in profit and returns 199.01 including the stake. To win exactly 100 you would stake 101.00.
What win rate do I need at -101?
The break-even win rate equals the implied probability, 50.25%. Winning more often than that at this price is profitable over the long run; winning less often loses money.