Calculator Use

Framing the odds ratio effect as a percentage reduction or increase completely dissociates the OR measure from an interpretation aligned with users’ expectations of analyses. In the colloquial interpretation, a 20% reduction does not correlate to, but implies a decrease from 100% to 80% or 20% reduction from some baseline. Converting odds into probability, we divide the odds by 1+ the odds e.g., if we have odds of 1:3, then we divide 1/3 by 4/3 which gives us a probability of 0.25 or 25%. Currently 4.28/5 1 2. Odds Conversion Calculator. Poker Odds Calculator Binomial Coefficient Calculator Conversion Calculator Poker Odds Chart Instructions About. Fill out one of the values, the other two will populate. Probability: Percentage: Odds::1. To calculate “+” odds, divide the odds by 100 and multiply that product by the amount of the wager. A $50 bet on the Tampa Bay Rays, for instance, would calculate as 140/100 (which yields 1.4. Positive odds - 100 divided by (the american odds plus 100), multiplied by 100 to give a percentage e.g. American odds of 150 = (100 / (150 + 100)). 100 = 40%.

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:

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 P_W = A / (A + B) while the probability of losing is given as P_L = B / (A + B).

Odds To Percent

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

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)

Further Reading

How does the overround calculator work?

The overround calculator takes all the possible outcomes from a given market, combining their priced probability to show you the overround percentage.

Use the Overround Calculator here

• Book %:
• Overround:

Odds To Percentage Calculator

What is overround?

Overround, also known as the book percentage, is the combined total of priced probability across all outcomes on a single event. The price of each event in a given market directly correlates to the percentage chance of that event winning. The overround adds all these percentages to give the bettor an idea of the formulation of the market. In a perfect world, these totals would add up to 100%, however in order for bookmakers to make profit on markets, it is not uncommon to see markets in the range of 120% - to 130%, and these are the markets bettors should try and avoid, instead trying to side with markets that closer to 100% and giving less of a margin to the bookmakers. In main markets such as moneyline and spread betting, the overround is typically low compared to prop bets such as to score the first basket because these prop bets have a higher variance so in order for the book to make consistent profit, they make the overround on these markets higher. Furthermore, in parlay bets, overround is compounded making the margins even greater for sportsbooks.

Using this calculator you can enter the prices of the events in a given market and produce the overround percentage of the market, showing you whether your pick and the market in total is offering a value opportunity.