Vig & No-Vig Fair Odds Calculator
Remove the overround from American odds, decimal odds, implied probabilities, or prediction market prices.
Results
Implied Probability A
52.4%
Implied Probability B
52.4%
Overround / Vig
+4.76%
No-Vig Fair Probability A
50.0%
Fair American odds: +100
No-Vig Fair Probability B
50.0%
Fair American odds: +100
What does this calculator do?
The vig calculator strips the house margin out of quoted market prices and shows you the true implied probability for each outcome. In a sportsbook, the implied probabilities usually add to more than 100%; that excess is the overround, also called vig or juice. On an exchange, use the executable YES and NO ask prices when you want to measure the cost of buying both sides. Midpoints or last-trade prices may add to exactly 100% and do not capture the bid-ask spread.
Enter American odds, decimal odds, implied probabilities, or market prices in cents for each side. The calculator computes the total overround, the vig percentage, and the no-vig fair probability for each outcome. For a two-outcome market priced at 55¢ and 52¢, the total is $1.07 — meaning the market contains 7% vig. The no-vig probability for each side is its price divided by the total, giving you the market's true estimate stripped of that margin.
This matters most when you're trying to assess whether your own probability estimate represents an edge over the market. If you think an event has a 60% chance and the no-vig price is 58%, you have a potential 2-point edge. But if you're comparing against the raw quoted price rather than the no-vig price, you might conclude you have a larger edge than actually exists. The no-vig price is the honest baseline for edge calculation.
Use this alongside the Expected Value calculator to measure your true edge, and the Market Fees calculator to factor in platform costs. All three together give you a complete picture of whether a trade is worth making.