No-Vig Fair Odds Calculator

What Are No-Vig Odds?

Sportsbooks build a margin (vig) into their odds so that the implied probabilities of all outcomes add up to more than 100%. No-vig odds remove this margin to show the true fair probabilities the market is pricing in. The question is how to distribute the vig removal between the two sides — and there's no single "correct" answer. This calculator shows four methods so you can compare.

Multiplicative (Proportional)

The most common method in the sharp betting community. Each side's implied probability is scaled down proportionally so they sum to 100%. Sides with higher implied probability absorb more of the vig in absolute terms, but the ratio between the two sides stays the same. Formula: fair = implied / total

Additive (Equal)

Splits the overround equally between both sides. Each side has the same absolute amount of vig removed. This gives a slight edge to the favorite compared to multiplicative. Formula: fair = implied - (overround / 2)

Conservative (Min)

The lower fair probability from multiplicative and additive for each side. This is the most conservative estimate of each outcome's true likelihood — useful when you want to be cautious about sizing a bet.

Why It Matters

No-vig odds are the foundation of +EV betting. If the fair probability under every method is lower than what the posted odds imply, you have a strong edge. If only the best-case method shows value, the edge is marginal. Comparing all four methods gives you a confidence range rather than a single point estimate.