How To Calculate Vegas Odds
Sorry, but there's a bit of math involved when it comes to calculating sports betting value.(Photo credit: DonkeyHotey / Foter / CC BY)
The way that sportsbooks manufacture their odds and betting lines has changed drastically over the years. The sports betting industry was once dominated by old-school Vegas oddsmakers, but much has changed since the advent of online sportsbooks, as well as. However, if you’re curious about the math, divide the number 36 by the number of squares your bet covers. Then subtract 1 from that figure to get the payout odds. For example, a three number bet. For fraction betting odds, the formula is: Denominator / (Denominator + Numerator) If the fraction betting odds are 11/10, the formula would look like this: 10 / (11+10) = 10 / 21 = 0.4761904. Multiply your end result (0.4761904) by 100 to get the percentage: 47.6%. A betting odds calculator and converter multiplies the stake by the odds to determine the potential profit on your sports betting wagers. Simply enter your stakes and odds, and our tools will tell you how much profit you should expect to receive using American, fractional or decimal odds.
Being able to convert betting odds into percentages is a major part of knowing how to read odds.
By knowing the percentage of the time you need to win a bet to break even, you can decide whether it is a smart bet to make. If you believe something has an 80% chance of occurring but the odds suggest it has a 50% chance of occurring, you have a positive expectation wager. If you believe something has an 80% chance of occurring but the odds suggest it has an 85% chance of occurring, it’s a bad bet to make because you have no edge.
Below are the formulas to convert moneyline betting odds to percentages, convert fraction betting odds to percentages, and convert decimal betting odds to percentages.
How to convert moneyline betting odds
Moneylines can come in ‘plus’ (favourites) and ‘minus’ (underdogs) formats, so there are two different formulas to convert moneylines into percentages.
For ‘plus’ moneylines, the formula is: 100 / (Moneyline + 100)
If the moneyline is +110, the formula would look like this:
100 / (110+100) = 100/210 = 0.476
Multiply your end result (0.476) by 100 to get the percentage: 47.6%
For ‘minus’ moneylines, the formula is: Moneyline / -(100 – (Moneyline))
If the moneyline is -130, the equation would look like this:
-130/ – (-130 -(-100)) = -130 / -230 = 130/230 = 0.565
Multiply your end result (0.565) by 100 to get the percentage: 56.5%
How to convert fraction betting odds
Fraction betting odds are easier to convert into an implied winning percentage.
For fraction betting odds, the formula is: Denominator / (Denominator + Numerator)
If the fraction betting odds are 11/10, the formula would look like this:
10 / (11+10) = 10 / 21 = 0.4761904
Multiply your end result (0.4761904) by 100 to get the percentage: 47.6%.
How to convert decimal betting odds
Decimal odds are the easiest to convert into a percentage.
For decimal betting odds, the formula is: 1 / decimal odds
If the decimal betting odds are 2.10, the equation would look like this:
1 / 2.10 = 0.4761904
How To Calculate Vegas Odds Without
Multiple your end result (0.4761904) by 100 to get the percentage: 47.6%.