1 2 Odds Calculator
For example, the exact mathematical equivalent of decimal odds 30 is fractional odds 29/1. However 29/1 is not used in betting markets, instead 30/1 is used, so that is what appears in this converter. For an explanation of the odds types on this table see decimal, fractional and American odds. A 1 in 500 chance of winning, or probability of winning, is entered into this calculator as '1 to 500 Odds are for winning'. You may also see odds reported simply as chance of winning as 500:1. This most likely means '500 to 1 Odds are against winning' which is exactly the same as '1 to 500 Odds are for winning.' To convert decimal odds to fractional odds, simply subtract 1 from the decimal, and then convert the remaining decimal number into a fraction. 2.5 – 1 = 1.5; 1.5 = 3/2. Converting American Odds/Moneyline Odds to Fractional & Decimal Odds. American odds are a little trickier, as they operate using positive and negative odds. If $10 is bet at odds of 3/1, the potential profit is $30 ($10 x 3) and the total returned is $40 ($30 plus the $10 stake). Implied Probability. Odds correlate to probability. A 4/1 bet is expected to win one in every five attempts, therefore the probability is 20%. Odds Conversion Table.
Calculator Use
Convert stated odds to a decimal value of probability and a percentage value of winning and losing. This calculator will convert 'odds for winning' an event or 'odds against winning' an event into percentage chances of both winning and losing.
Be careful if you are using sports teams odds or betting odds. If you see that the Patriots super bowl odds are 9/2, that is most likely 'odds against' and should be entered in the calculator with 'Odds are: against winning.'
When playing a lottery or other games of chance be sure you understand the odds or probability that is reported by the game organizer. A 1 in 500 chance of winning, or probability of winning, is entered into this calculator as '1 to 500 Odds are for winning'. You may also see odds reported simply as chance of winning as 500:1. This most likely means '500 to 1 Odds are against winning' which is exactly the same as '1 to 500 Odds are for winning.'
Probability Formulas:
1/2 Odds Calculator
This calculator will convert 'odds of winning' for an event into a probability percentage chance of success.
Odds, are given as (chances for success) : (chances against success) or vice versa.
If odds are stated as an A to B chance of winning then the probability of winning is given as PW = A / (A + B) while the probability of losing is given as PL = B / (A + B).
For example, you win a game if you pull an ace out of a full deck of 52 cards. Pulling any other card you lose. The chance of winning is 4 out of 52, while the chance against winning is 48 out of 52 (52-4=48). Entering A=4 and B=48 into the calculator as 4:48 odds are for winning you get
2 To 1 Odds Mean
For 4 to 48 odds for winning;
Probability of:
Winning = (0.0769) or 7.6923%
Losing = (0.9231) or 92.3077%
'Odds for' winning: 1:12 (reduced from 4:48)
'Odds against' winning: 12:1 (reduced from 48:4)
