1/25 Fractional Odds Explained
- Decimal
- 1.04
- American
- -2,500
- Fractional
- 1/25
- Implied probability
- 96.15%
- Polymarket
- 96¢
- $100 wins
- 4.00
- American
- -2,500
- Fractional
- 1/25
- Implied probability
- 96.15%
- Polymarket
- 96¢
- Profit
- 4.00
- Total return
- 104.00
1.040 decimal, -2,500 American, 96.15% implied probability
At 1/25 a 100 stake returns 104.00: the 100 back plus 4.00 profit. Decimal bettors know the price as 1.04, American bettors as -2,500, and prediction-market traders as a 96¢ share.
What 1/25 pays
Profit is stake multiplied by the fraction; add the stake back for the total return. A 100 stake wins 4.00 and returns 104.00.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 0.40 | 10.40 |
| 25 | 1.00 | 26.00 |
| 50 | 2.00 | 52.00 |
| 100 | 4.00 | 104.00 |
| 500 | 20.00 | 520.00 |
| 1,000 | 40.00 | 1,040.00 |
Break-even and long-run results
The implied probability of 1/25 is bottom divided by top-plus-bottom, which is 96.15%. Win more often than that and you profit over time.
| Win rate | Return on stake |
|---|---|
| 50% | -48.0% |
| 55% | -42.8% |
| 60% | -37.6% |
| 65% | -32.4% |
| 96% | -0.2% |
1/25 is odds-on and short: the implied probability is 96.15%. Fractional prices below 1/3 are where the risk of a run of small wins being undone by a single loss is highest.
Converting 1/25 by hand
Divide the top of the fraction by the bottom and add one for the decimal price, 1.04. For the implied probability, divide the bottom by the sum of top and bottom: 96.15%. American odds follow from the decimal price: odds-on, so −100 divided by (1.04 − 1) gives -2,500. The same chance on a prediction market is a 96¢ share.
The vig at 1/25
With both sides of a two-way market at 1/25, implied probabilities would sum to 92.31% above 100%: a 48.00% margin on stakes. The fair price would be 2.00 decimal each side. Try other markets in the devig calculator.
1/25 on a betting exchange
On an exchange 1/25 is worth 1.039 decimal after 2% commission and 1.038 after 5%. Compare with the bookmaker before choosing where to bet.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.039 | -2,551 | 96.23% |
| 5% | 1.038 | -2,632 | 96.34% |
Neighbouring rungs on the ladder
Fractional prices move in fixed rungs rather than smooth steps, so a bookmaker who wants to shorten 1/25 slightly has to jump to the next rung down, and the size of that jump depends on where you are on the ladder. The nearby prices listed below are the rungs on either side of 1/25; each link opens the same set of facts for that price, which is the quickest way to see how much a one-rung move changes the implied probability and the payout.
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does 1/25 mean in betting?
Fractional odds of 1/25 pay the top number in profit for every bottom number staked. A 100 stake wins 4.00 and returns 104.00. The implied probability is 96.15%.
What is 1/25 in decimal odds?
1/25 is 1.04 in decimal odds: divide the top by the bottom and add 1.
What is 1/25 in American odds?
1/25 converts to -2,500 in American odds.
Is 1/25 a good price?
A price is good only relative to the true chance. 1/25 implies 96.15%; if you believe the outcome is more likely than that, the price has value. Compare it with a devigged market to check.
Why do bookmakers use a ladder of fractions?
Tradition and readability: prices such as 6/4, 100/30 and 11/10 are quoted instead of their reduced forms because they are what racecourse bookmakers have always used. Decimal odds show the same prices with finer steps.