Closing Line Value Calculator
Measure the quality of your bet timing by comparing the odds you received to the final closing line. Positive CLV signals that you consistently bet into underpriced markets before the bookmaker corrects them.
About this calculator
Closing line value (CLV) measures how much better or worse your bet odds were compared to the odds available at market close, just before the event begins. The formula is: CLV (%) = ((betOdds − closingOdds) / closingOdds) × 100. A positive CLV means you received higher odds than the closing price, indicating you identified value before the market priced it out. Closing odds are widely regarded as the most accurate reflection of true event probability, since sharp money and public action have had the maximum time to correct inefficiencies. Bettors who consistently achieve positive CLV are extracting value from markets, and research shows that positive CLV is a stronger predictor of long-run profitability than short-term win/loss records. Tracking CLV across all bets provides an objective measure of betting skill independent of results.
How to use
Example: You bet on a team at decimal odds of 2.20. By kick-off, the closing odds on the same market are 1.95. Step 1: Enter betOdds = 2.20 and closingOdds = 1.95. Step 2: CLV = ((2.20 − 1.95) / 1.95) × 100 = (0.25 / 1.95) × 100 = 12.82%. Step 3: A CLV of +12.82% means you obtained odds that were 12.82% better than the closing line — strongly positive. Step 4: Optionally enter your stake to see the implied expected value advantage captured on this bet. Repeat across all bets to track average CLV over time.
Frequently asked questions
Why is closing line value considered a better performance metric than win rate?
Win rate is subject to significant variance in the short term — a skilled bettor can lose streaks and a lucky bettor can win streaks, making it unreliable over small samples. CLV removes outcome variance by comparing your odds to the market consensus at close, which research shows is the best available proxy for true probability. Consistently beating the closing line suggests your bets were made at positive expected value, meaning skill rather than luck is driving results. Most professional sports bettors track CLV as their primary performance indicator precisely because it is outcome-independent.
How can bettors systematically improve their closing line value over time?
Improving CLV requires acting earlier in the market lifecycle, before sharp money moves the line toward fair value, or identifying markets where you have a genuine informational edge over the bookmaker. Specialising in niche markets — lower leagues, specific props, or in-play opportunities — where bookmakers have less pricing expertise tends to offer more CLV opportunities. Shopping across multiple sportsbooks to consistently find the best available odds also directly improves average CLV. Keeping detailed records of bet timing and CLV by market type helps identify where your edge is strongest.
What level of closing line value is considered good for a sports bettor?
Even a sustained average CLV of 2–3% is considered excellent in efficient markets such as major football leagues or NFL spreads, where sharp money quickly corrects mispriced lines. In softer markets or with early-bird pricing, CLV of 5–10% per bet is achievable for skilled bettors. Negative CLV over a large sample (50+ bets) is a strong warning sign that you are consistently betting into overpriced markets or too close to closing when lines have already been sharpened. Most recreational bettors unknowingly have negative CLV, which explains why the vast majority of sports bettors lose money over time.