In sports betting, short-term win-loss record can be misleading. A good bet can lose, and a poor bet can win. Closing Line Value, or CLV, measures whether the odds you took were better or worse than the market price available near the close.
This CLV Calculator compares your bet price with the closing price and can also remove the bookmaker margin from a two-way closing market. The no-vig version is usually the cleaner benchmark because it compares your bet against a fairer estimate of the closing probability.
Important: CLV is a process metric, not a guarantee of profit. A single bet with positive CLV can lose. A short sample can be noisy. CLV becomes more meaningful when tracked consistently across hundreds or thousands of bets in comparable markets.
Quick Answer: How to Read CLV
- Positive CLV: you took a better price than the closing line.
- Negative CLV: the market closed at a better price than the one you took.
- Raw CLV: compares your odds directly against the closing odds, including vig.
- No-vig CLV: removes the margin from the closing market before comparison.
- Probability-point CLV: shows how much implied probability moved between your bet and the close.
Closing Line Value Calculator
Calculate raw CLV, no-vig CLV, probability movement, and stake-level impact.
How to Use the CLV Calculator
- Select odds format: Use decimal odds or American odds.
- Enter odds you took: This is the price from your original bet slip.
- Enter closing odds: Use the closing price for the same outcome and market.
- Optional: enter opposite-side closing odds: This lets the calculator remove vig from the closing market.
- Optional: enter stake: The calculator estimates the expected-value difference implied by the CLV.
Raw CLV Formula
For decimal odds, raw CLV is:
Raw CLV = (Odds Taken ÷ Closing Odds – 1) × 100
Example:
- Odds taken: 2.05
- Closing odds: 1.95
- Raw CLV: (2.05 ÷ 1.95 – 1) × 100 = +5.13%
This shows you beat the displayed closing price. However, the displayed closing price still contains bookmaker margin.
Why No-Vig CLV Is Usually Cleaner
A two-way closing market contains margin. For example, if both sides close at 1.95, the total implied probability is:
1 ÷ 1.95 + 1 ÷ 1.95 = 102.56%
The extra 2.56 percentage points are market margin. To estimate a fair closing price, the calculator normalizes both sides back to 100%.
Worked Example
You bet an outcome at 2.05. It closes at 1.95, and the opposite side also closes at 1.95.
- Raw CLV: +5.13%
- Closing market overround: 102.56%
- No-vig fair closing odds: 2.00
- No-vig CLV: (2.05 ÷ 2.00 – 1) × 100 = +2.50%
The no-vig figure is lower because it removes the closing market margin.
CLV Benchmarks
Benchmarks depend heavily on market type, limits, sport, timing, and source of the closing line. A small positive CLV in a liquid market may be meaningful, while a larger figure in a low-limit prop market may be less stable.
| Average no-vig CLV | Possible interpretation | Caution |
|---|---|---|
| +4% or higher | Strong signal in softer or inefficient markets. | Hard to sustain in liquid main markets. |
| +1% to +4% | Potentially sharp if repeated over a large sample. | Needs many bets to verify. |
| -1% to +1% | Near market price. | Could be noise, especially in small samples. |
| Below -1% | The market often moved against your price. | Review model, timing, and line source. |
Which Closing Line Should You Use?
Use a closing line that reflects a liquid and competitive market. Many bettors use market-making or sharper books as benchmarks because those prices often incorporate more sophisticated action near close. However, the best benchmark can differ by sport, jurisdiction, limits, and market type.
For niche player props or local markets, the “best” closing line may be harder to define. In those cases, track the same source consistently and do not overread small samples.
CLV for Spreads and Totals
This calculator works best when the price changes but the outcome definition is the same. Spreads and totals can move in both price and points. For example:
- Rams -2.5 at -110 closes Rams -3.5 at -110.
- Over 44.5 at -105 closes Over 45.5 at -115.
Those examples require converting point movement into price value, especially around key numbers. A raw odds-only CLV calculator cannot fully capture that without a point-value model.
Calculator Limitations
- The no-vig mode assumes a two-way market.
- Three-way markets such as soccer 1X2 need a three-outcome no-vig method.
- Point-spread and totals CLV can require key-number adjustments.
- Single-bet CLV is not statistically meaningful by itself.
- Closing lines can differ by sportsbook, limit, market type, and timing.
- CLV does not remove variance from actual betting results.
Frequently Asked Questions
What is closing line value?
Closing line value measures whether the odds you took were better or worse than the odds available near market close.
Does positive CLV guarantee profit?
No. Positive CLV can still lose on any single bet. It is more useful as a long-run process metric across a large sample.
What is no-vig CLV?
No-vig CLV removes the bookmaker margin from the closing market before comparing your price with the fair closing price.
Why does raw CLV overstate edge?
Raw CLV compares against a closing price that still includes vig. No-vig CLV normalizes the closing market to remove that margin.
Can I calculate CLV for parlays?
For standard parlays, you can calculate CLV leg by leg and then combine fair probabilities. Same-game parlays are harder because correlation between legs must be modeled.
Responsible gambling notice: CLV is an analytical metric, not a guarantee of profit. Even a bettor with positive average CLV can experience long losing streaks. Never wager more than you can afford to lose.