📘 Published October 29, 2026 · 5 min read
Decimal, American and fractional odds: how to read and convert them
1.91, -110 or 10/11? The same price written three ways. The Teacher explains decimal, American and fractional odds, how to convert them, and what each one tells you about your chances, with a converter.
Three ways to write the same price
Every sportsbook price says the same thing: how much you get back if your bet wins. Decimal odds and American odds simply write it differently.
A decimal price of 1.91, an American price of -110 and a fractional price of 10/11 are exactly the same bet: on OufBet you can show any of them with the format choice at the top of every page.
Decimal odds: what you get back
Decimal odds give the total amount returned for every $1 staked, stake included.
- At 2.50, a $10 bet returns $25: $15 of profit plus your $10 stake.
- At 1.50, a $10 bet returns $15: $5 of profit.
- The profit is always the stake multiplied by (odds - 1).
💡 The higher the decimal price, the bigger the payout and the less likely the outcome according to the sportsbook.
American odds: + for underdogs, - for favourites
American odds are built around a $100 bet.
- A plus sign gives the profit on a $100 bet: at +150, $100 wins $150.
- A minus sign gives what you must bet to win $100: at -200, you bet $200 to win $100.
- +100 and -100 both mean an even bet: you win as much as you stake.
Fractional odds: the British way
Fractional odds give the profit compared with the stake: the first number is what you win for the second number you bet.
- At 5/2, every $2 bet wins $5 of profit: a $10 bet returns $35.
- At 10/11, you bet $11 to win $10.
- 1/1 is an even bet, often called evens.
Convert one into the other
🧮 The odds converter
- Decimal 2.00 or more → American: (decimal - 1) × 100, with a plus sign. 2.50 → +150.
- Decimal under 2.00 → American: -100 ÷ (decimal - 1). 1.50 → -200.
- American plus → decimal: 1 + (American ÷ 100). +150 → 2.50.
- American minus → decimal: 1 + (100 ÷ American, without the sign). -200 → 1.50.
- Decimal → fractional: (decimal - 1) as a fraction. 2.50 → 3/2, often written 6/4.
- Fractional → decimal: 1 + (first number ÷ second number). 10/11 → 1.91.
| Decimal | American | Fractional | Implied chance | Profit on $10 |
|---|---|---|---|---|
| 1.50 | -200 | 1/2 | 66.7% | $5.00 |
| 1.91 | -110 | 10/11 | 52.4% | $9.10 |
| 2.00 | +100 | 1/1 | 50.0% | $10.00 |
| 2.50 | +150 | 6/4 | 40.0% | $15.00 |
| 3.00 | +200 | 2/1 | 33.3% | $20.00 |
| 5.00 | +400 | 4/1 | 20.0% | $40.00 |
From the price to the chance
Every price hides a probability: 1 ÷ decimal odds. At 2.50, the sportsbook gives the outcome 1 ÷ 2.50 = 40%.
Add the chances of every outcome of a market and you get more than 100%: the difference is the sportsbook's margin. That is why OufBet shows the payout of each sportsbook, the share of the stakes it gives back, and removes the margin to show each team's fair chance.
💡 Whatever the format, compare the same bet across sportsbooks: a better price is money back in your pocket over a season.
Odds move fast: always check the price on the sportsbook's site. Information, not betting advice.