No-Vig Fair Odds Calculator
The house always wins because they artificially inflate probabilities. Remove the Vig from any two-way market to discover the true, mathematically fair betting line.
Last updated: February 24, 2026
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American odds (e.g. -110)
American odds (e.g. +100)
Fair True Odds (No-Vig)
Side 1
+100
50.0% implied
Side 2
+100
50.0% implied
Total Implied Target
104.76%
Bookmaker's Margin
4.76%
The Mathematics of the Sportsbook
A fair coin flip has a 50% chance of Heads and a 50% chance of Tails. The probabilities add up to precisely 100%. A sportsbook offers -110 on both sides. Evaluated mathematically, -110 implies a 52.4% probability. 52.4 + 52.4 = 104.8%. This excess 4.8% is called the overround.
To find the true probability, we must scale those inflated, vig-heavy probabilities back down so they equal 100%. If Team A's vig-inflated probability is 60% and Team B's is 45% (Total 105%), dividing 60 by 105 gives Team A a mathematically true win probability of 57.14%.
Why do this? You use the No-Vig calculator on the sharpest sportsbook in the world to find what the "True Line" is. If the sharp book says the True Line is -130 (56.5% chance), but your local sportsbook is offering -115 (53.5% implied), you have a mathematical edge over your local book.
Frequently Asked Questions
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Stop betting blindly. Share this fair-odds calculator with your trading syndicate or betting group to ensure you're only taking mathematically sound positions.
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