Closing Line Value Calculator
Enter the odds you bet at and the closing odds. The calculator returns your CLV percentage, both implied probabilities, and — if you add the other side of the closing market — the no-vig fair price and the expected value of your stake.
Closing implied probability: 54.55% · No-vig and EV require the other side of the closing market.
How closing line value is calculated
CLV compares the price you took with the market's final price. Both odds are converted to decimal form, then:
Positive CLV means you bet at a better price than the market settled on. Averaging +1% to +2% CLV across hundreds of bets is the standard professional benchmark, and it predicts long-term profit far better than win rate does.
Why the no-vig price matters
A closing line still includes the book's margin. Adding the opposite side lets the calculator strip that margin out and return the market's true probability estimate:
With that fair probability and your stake, the expected value of the bet follows directly — which is the number that tells you whether the bet was worth placing, no matter how it settled.
Track CLV automatically instead
Running this calculation by hand works for one bet. Across a season it becomes a spreadsheet problem. Evrai logs every bet across sportsbooks, Kalshi, and Polymarket, pulls the closing price, and computes CLV, ROI, and Kelly sizing for you.
For the full background, read what closing line value is and how to calculate CLV step by step.
Track CLV on every bet automatically.
One dashboard for sportsbooks, Kalshi, and Polymarket — CLV, ROI, and Kelly sizing. No credit card required.