No Vig Fair Odds Calculator for Sports Betting

By using a no-vig fair odds calculator, you’ll discover the “true” odds of a wager on 2-outcome events. 

What does that mean? Well, it’ll cut through the vig, which is a built-in commission for online sportsbooks, and reveal what the odds would be if the sportsbook didn’t factor in that commission. 

Below, I’ll dive more into what a no-vig fair odds calculator is, how to use it, and provide a real-world example that helps it make more sense. 

Let’s dive in. 

How to Use the No Vig Calculator

To use a no-vig fair odds calculator, you’ll plug in the odds provided by the sportsbook. From there, you’ll hit calculate, and it’ll show the true probability and the no-vig odds. 

What’s the formula behind it? There’s a different one per the type of odds. 

Let’s look at this with odds of -120 and +100. 

First, you’ll want to convert the odds to the implied probability. 

• Negative Odds Implied Probability: |odds| / (|odds| + 100). So for -120, that becomes 120 / (120 + 100) = 120 / 220 = 0.5455 or 54.55%.

• Positive Odds Implied Probability: 100 / (odds + 100). So for +100, it becomes 100 / (100 + 100) = 100 / 200 = 0.500, or 50.00%.

From here, you add these figures together, which would be 104.55%. 

Next, you remove the vig to then make the probabilities add to 100%. 

• No-Vig Probability: Original Implied Probability / Total x 100. 

Using that formula with 54.55 / 104.55 x 100, it’s 52.17%. For 50%, it’s 50.00/104.55 x 100, and that’s 47.83%. 

Next, you turn the new probabilities back into odds. That’s done by taking 100 / the new percentage figure after removing the vig. 

In the example above, the former is -109, and the latter is +109.0 

No Vig Fair Odds Explained 

The goal of using a no-vig fair odds calculator is to see the true odds of a wager without factoring in the cut the sportsbook gets from you making the wager. 

Think of it like this: After doing the calculations, you’ll see what the line should be if the sportsbook wasn’t trying to make a bit of money. 

As mentioned, vig is a term used, which is essentially the fee or commission the sportsbook “charges you” for making a wager on their platform. 

This system is used by sharp bettors to determine if the bet has a positive expected value (EV), which is another metric used to determine how much money you can expect to win or lose on average per bet over the long run. 

By determining the “no vig” value, you can compare odds between sportsbooks and identify lines that are mispriced. 

No Vig Fair Odds Calculator Example

Now that we’ve learned all about no-vig fair odds calculators, what they mean, and more, let’s look at a real-world example using the opening night of the NFL season between the Philadelphia Eagles and Dallas Cowboys. We’ll examine the moneyline, which are the Eagles at -330 and the Cowboys at +265. 

Using the formulas above, here’s how it works out: 

• -330 Implied Probability: 76.74%

• +265 Implied Probability: 27.39%

• Added together: 104.13%, or a vig of 4.13%. 

Next up, you normalize it to get it back to 100%. This results in 73.69% and 26.31%. 

Now, if you convert the odds, it would be -280 and +280.