Fair Odds Calculator
The fair odds behind any sportsbook market are the prices that would exist with no margin baked in. Enter both sides and we'll show you the true, fair value — the break-even line where neither side has an edge.
What "fair odds" actually means
Fair odds reflect the true probability of an outcome — the price you'd pay (or receive) if the sportsbook took no margin. In a perfectly fair market, the two sides' implied probabilities would sum to exactly 100%.
Real sportsbook lines sum to 102–110% because the book builds in a margin. Strip that margin out — proportionally across both sides — and you're left with the fair odds.
Why fair odds matter
- It's your benchmark. Every +EV decision is your price vs. the fair price.
- It exposes weak boosts. Many sportsbook boosts are still worse than fair — fair odds show that instantly.
- It tells you the true win rate. You need to win at the fair probability to break even.
- It's market-derived, not opinion. Fair odds come from the market itself, not a model or a tout.
Worked example — Bills vs. Chiefs moneyline
- 1Posted price: Bills +120 / Chiefs −140
- 2Bills implied prob: 100 / (120 + 100) = 45.45%
- 3Chiefs implied prob: 140 / (140 + 100) = 58.33%
- 4Sum: 103.78%Book hold = 3.78%
- 5Fair Bills prob: 45.45 / 103.78 = 43.79%Fair price ≈ +128
- 6Fair Chiefs prob: 58.33 / 103.78 = 56.21%Fair price ≈ −128
Frequently asked questions
What are fair odds?+
Fair odds reflect the true probability of an outcome — the price you'd get if the sportsbook took no margin. In a perfectly fair two-way market, the two sides' implied probabilities sum to exactly 100%.
How do I find fair odds for a bet?+
Take a sharp book's two-sided price (Pinnacle is the gold standard), convert each side to implied probability, then divide each by the sum of both. Convert that fair probability back to American odds.
Why don't sportsbooks just post fair odds?+
Because vig is how they make money. A typical US book runs a 4–6% hold on moneylines and 6–10% on player props. The fair price is the break-even line; everything above that hold is the book's profit.
Are fair odds the same as 'true' odds?+
Effectively yes — both terms mean the price that matches the real probability of the event. We use 'fair' because it emphasizes the bet is neither +EV nor −EV at that price.
Can I beat the book just by knowing fair odds?+
Only if you can consistently find sportsbooks offering better-than-fair prices. That happens with boosts, soft books, stale lines, and bonus bet conversions. Knowing the fair price tells you which of those opportunities are real.
One step further
The Bet Analyzer compares your sportsbook's price to live fair odds from multiple books — and returns a single A–F grade plus edge % and expected value.