Find fair odds / Free calculator
No-Vig Calculator
A sportsbook builds a margin into its prices. This no-vig fair odds calculator removes that overround proportionally, so you can compare both sides on a probability scale that adds up to 100%.
Your inputs
Instant calculationChanging formats resets odds to even money.
Your results
Based on your inputs. Before fees, rounding, and venue-specific settlement rules.
How to use the no-vig calculator
Enter the prices for both outcomes of the same market. The calculator converts each price to an implied probability, adds them together, then divides each probability by that total. It also converts the normalized probabilities back to fair decimal odds.
Fair probability A = (1 / decimal odds A) ÷ [(1 / decimal odds A) + (1 / decimal odds B)]A worked example
At −110 on each side, the implied probabilities are 52.38% and 52.38%. The overround is 4.76 percentage points. After proportional removal, each side is 50.00%, equivalent to 2.00 decimal odds or +100 American odds.
What the numbers can tell you
“Fair” here means normalized market prices, not a verified prediction. Different methods of removing vig can produce different estimates, especially for longshots. This calculator uses proportional normalization.
Frequently asked questions
Is the vig the same as the bookmaker’s profit?
No. Overround measures the excess of implied probabilities above 100%. Realized profit depends on the stakes accepted, outcomes, promotions, and settlement rules.
Can I use this for Novig or prediction markets?
Yes, to compare complementary outcome prices on a common scale. No-vig calculations do not include exchange fees, spreads, or liquidity, and the name does not imply an affiliation with Novig.