How to Calculate No-Vig (Fair) Odds

To find positive expected value (+EV), you must first know the fair price of a bet. This guide shows you how to strip the sportsbook's juice to reveal the true probability.

What Is the Vig?#

The vig (short for vigorish) or juice is the fee a sportsbook charges for taking your bet. Sportsbooks do not offer the true mathematical probability of an event. They shade the odds so they have an edge regardless of the outcome.

For example, a fair coin flip should be +100 on both sides (50/50). But a sportsbook prices both sides at -110, giving them a built-in profit margin.

Why You Need No-Vig Odds#

If you want to find +EV bets, you need to know the fair probability first. Without removing the juice, you are comparing your estimate against an inflated number that already includes the house edge.

No-vig odds give you the baseline. From there, you can compare your own projection to the fair price and decide if there is value.

How to Calculate No-Vig Odds#

Follow these four steps:

Step 1: Convert to Implied Probability#

Turn the American odds for both sides into implied probabilities.

• Team A at -150: 150 / (150 + 100) = 60.00%
• Team B at +130: 100 / (130 + 100) = 43.48%

Step 2: Calculate the Overround#

Add the implied probabilities together:

60.00% + 43.48% = 103.48%

The 3.48% above 100% is the house's juice. A fair market totals exactly 100%.

Step 3: De-Vig Each Probability#

Divide each implied probability by the total overround:

• Fair Prob Team A: 60.00 / 103.48 = 57.98%
• Fair Prob Team B: 43.48 / 103.48 = 42.02%

Now the probabilities sum to 100% — the house edge is removed.

Step 4: Convert Back to Odds#

Turn the fair probabilities back into American odds:

• Fair Odds Team A: -138 (from 57.98%)
• Fair Odds Team B: +138 (from 42.02%)

These are the prices you should compare against when evaluating value.

3-Way Markets#

The same method works for markets with three outcomes (such as soccer: Win / Draw / Lose). Convert all three sides to implied probabilities, sum them, and divide each by the total. The overround is typically larger in 3-way markets because there are more outcomes for the book to shade.

Using the No-Vig Calculator#

You can skip the manual math entirely. The No-Vig Calculator on this site handles 2-way and 3-way markets automatically. Enter the odds from your sportsbook, and it shows:

• Fair probability for each outcome
• Total overround and juice percentage
• Optionally, compare your book's odds to see your edge and expected value

Pair it with the +EV Calculator to evaluate whether a specific bet has long-run value based on your projection.