NFL tool
NFL Vig Calculator
See the overround hiding inside a two-way market, then compare the price with a proportional fair-price estimate.
Market hold
4.76%
Favorite implied
52.38%
Underdog implied
52.38%
This estimates the two-way overround from the prices you enter. It does not account for alternate lines, tied outcomes, exchange fees, or operator-specific settlement rules.
What this tool shows
Enter the favorite and underdog prices exactly as displayed. The calculator converts each to implied probability, adds them together, and shows the overround above 100%. It then normalizes the two probabilities proportionally as an illustrative fair-price adjustment.
This does not reveal the operator’s actual risk book, account limits, exchange fees, or the true probability of the event. For the full explanation, read How NFL Odds Work.
What is vig?
Vig is the pricing margin built into a market. In a two-way market, the implied probabilities usually add to more than 100%; the excess is the overround or hold estimate.
Is the fair price from this calculator truly fair?
It is a proportional normalization of the prices you entered, useful as a reading aid. It is not a model of the teams or a guarantee of fair value.