3.55 Decimal Odds Explained
- Decimal
- 3.55
- American
- +255
- Fractional
- 51/20
- Implied probability
- 28.17%
- Polymarket
- 28¢
- $100 wins
- 255.00
- American
- +255
- Fractional
- 51/20
- Implied probability
- 28.17%
- Polymarket
- 28¢
- Profit
- 255.00
- Total return
- 355.00
3.550 decimal, +255 American, 28.17% implied probability
3.55 is the decimal way of writing a price that Americans call +255 and British bookmakers call 51/20. Decimal odds are the easiest to compute with: multiply the stake by 3.55 for the total return, and divide one by 3.55 for the implied probability of 28.17%.
What 3.55 pays
Multiply the stake by 3.55 to get the total return. A 100 stake returns 355.00, of which 255.00 is profit. To win 100 in profit you would need to stake 39.22.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 25.50 | 35.50 |
| 25 | 63.75 | 88.75 |
| 50 | 127.50 | 177.50 |
| 100 | 255.00 | 355.00 |
| 500 | 1,275.00 | 1,775.00 |
| 1,000 | 2,550.00 | 3,550.00 |
Break-even and long-run results
One divided by 3.55 is 28.17%: the implied probability, and the win rate at which betting this price neither makes nor loses money. The rows below show the return on stake at several win rates.
| Win rate | Return on stake |
|---|---|
| 28% | -0.6% |
| 50% | 77.5% |
| 55% | 95.3% |
| 60% | 113.0% |
| 65% | 130.8% |
At 3.55 the implied chance is 28.17%, a moderate underdog. Each win pays 255.00 per 100, and wins come less than half the time by the bookmaker's estimate. Compare prices across several books at this level: outsiders are where they disagree most.
Converting 3.55 by hand
Every other format follows from the decimal price in one step. Implied probability is one divided by 3.55, which gives 28.17%. American odds depend on which side of 2.00 the price sits: at or above 2.00, multiply (3.55 − 1) by 100 to get +255. The fraction is 3.55 − 1 written as a ratio and snapped to the nearest traditional price, 51/20. A prediction market simply quotes the probability in cents: 28¢.
The vig at 3.55
If both sides of a two-way market were 3.55, their implied probabilities would sum to -43.66% above 100%. That is the overround; as a share of stakes it is a -77.50% margin. The fair price with the margin removed is 2.00 on each side. The devig calculator does this for any market and any method.
3.55 on a betting exchange
Exchange commission comes off winnings, so 3.55 at 2% commission is really 3.499, and at 5% it is 3.423. The break-even win rate rises accordingly.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 3.499 | +250 | 28.58% |
| 5% | 3.423 | +242 | 29.22% |
Same price in other formats
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does 3.55 decimal odds mean?
Decimal odds of 3.55 return 3.55 for every 1.00 staked, including the stake, so the profit is 3.55 minus 1. The implied probability is 28.17%.
What is 3.55 in American odds?
3.55 decimal is +255 in American odds. Prices of 2.00 and above convert with (decimal − 1) × 100; prices below 2.00 with −100 / (decimal − 1).
What is 3.55 as a fraction?
3.55 is 51/20 in fractional odds: subtract 1 from the decimal price and express the result as a fraction.
How much does 100 return at 3.55?
100 × 3.55 = 355.00 total return, of which 255.00 is profit.
What win rate breaks even at 3.55?
1 / 3.55 = 28.17%. Win more often than that and the price is profitable; the bookmaker's margin means both sides of a market usually sit a little under fair.