This CLV calculator measures the one number sharp bettors care about more than their win rate: how your price compares with the closing line. Say you bet a team at +120 on Tuesday and by kick-off they’re +105, with the other side -125. Take the vig out of the close and the fair price is about +114. You got +120, so you beat the close by roughly 2.9%. Do that consistently and you’re very likely a long-term winner, whatever this week’s results say. The calculator is free and works with American, decimal or fractional odds.
Why closing line value matters
A season of results is noisy. Hit 55% over 200 bets and you could still be a break-even bettor who ran well. The closing line is different: it’s the market’s best estimate once all the money and information is in. If you keep getting better prices than that estimate, you’re finding value before the market does. Bettors and bookmakers both use CLV this way, which is also why accounts that beat the close regularly tend to get limited.
Measuring it properly
Comparing +120 with +105 directly isn’t quite fair, because +105 still has the book’s margin baked in. That’s why there’s a box for the closing price on the other side. With both sides, the calculator de-vigs the close using the multiplicative method and gives you the true edge. With only your side, it uses the raw closing price and tells you the figure is understated.
Fair closing chance = your side ÷ (your side + other side) CLV = fair closing chance × odds you took − 1
Want the fair line on its own? The no-vig calculator has three de-vig methods. To keep a running record of your bets and their CLV, the bet tracker does the logging for you.
A few honest caveats
CLV only means something against a liquid close. A lower-league match with thin limits can close anywhere. And small samples still lie: 20 bets with positive CLV is encouraging, 500 is evidence.
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