Odds converter
Type a price in any format and read it in the other two, together with the probability it implies. Decimal, fractional and American odds describe the same price in different ways.
- Decimal
- 2.5
- Fractional
- 3/2
- American
- +150
- Implied probability
- 40.00%
Common prices in every format
| Decimal | Fractional | American | Implied probability |
|---|---|---|---|
| 1.25 | 1/4 | -400 | 80.00% |
| 1.5 | 1/2 | -200 | 66.67% |
| 1.91 | 91/100 | -110 | 52.36% |
| 2 | 1/1 | +100 | 50.00% |
| 2.5 | 3/2 | +150 | 40.00% |
| 3 | 2/1 | +200 | 33.33% |
| 4 | 3/1 | +300 | 25.00% |
| 6 | 5/1 | +500 | 16.67% |
The three odds formats
Decimal odds show what one unit staked returns, including the stake: at 2.50, staking 10 returns 25. Fractional odds show the profit against the stake: at 3/2, staking 2 wins 3. American odds show the profit on a 100 stake for positive prices, and the stake needed to win 100 for negative prices: +150 wins 150 on 100, and -200 needs 200 to win 100.
How to convert
Everything converts through decimal odds. From fractional a/b, decimal = 1 + a ÷ b. From a positive American price, decimal = 1 + price ÷ 100. From a negative American price, decimal = 1 + 100 ÷ the price without its minus sign. The implied probability is 1 ÷ decimal.
What the implied probability means
It is the chance the price implies, margin included. A sportsbook's prices for all outcomes of an event add up to more than 100%, and the surplus is its margin, so the implied probability of a single price is a little higher than the sportsbook's own estimate. The implied probability calculator shows the margin and the fair prices with it removed.
Frequently asked questions
How do I convert American odds to decimal?
For a positive price such as +150, add 1 to the price divided by 100: 1 + 150 ÷ 100 = 2.50. For a negative price such as -200, add 1 to 100 divided by the price without its minus sign: 1 + 100 ÷ 200 = 1.50.
How do I convert decimal odds to fractional?
Subtract 1 from the decimal odds and write the result as a fraction. Decimal 2.50 minus 1 is 1.5, which is 3/2. Decimal 1.91 minus 1 is 0.91, which is 91/100, and sportsbooks usually round it to 10/11.
What does -110 mean?
You must stake 110 to win 100. In decimal odds that is 1.909, and it implies a probability of 52.38%.
What are fractional odds?
Fractional odds state the profit against the stake. At 5/1 you win 5 for every 1 staked and get the stake back as well, which is decimal 6.00. Evens is 1/1, decimal 2.00.
Why do the probabilities of both sides add up to more than 100%?
The excess is the sportsbook's margin, also called the overround. When the best prices from different sportsbooks add up to less than 100%, an arbitrage exists.
BETCYON does not place bets.