Tool · Positive-EV betting
Closing line value calculator (CLV)
Measure how your bet's price compares with the closing line, raw or with the closing vig removed, and see the implied probability at each price.
Reviewed by Owen DavidsUpdated Oct 30, 2026Facts checked Oct 30, 2026
On this page
A closing line value calculator measures how the odds you took compare with the market's final price before the event. Beating the close consistently is one of the best available signs that a bettor's prices are good. Enter your odds and the closing odds below; add the other side to remove the closing margin.
Closing line value (CLV) calculator
Same market and sportsbook as the close above
- CLV vs no-vig close
- +5.21%
- Also the estimated EV if the close is right
- CLV vs raw close
- +10.00%
- Includes the closing vig
- Fair closing odds
- 2.091
- 47.8% no-vig probability
- Implied probability
- 45.5% → 50.0%
- Your price → the close
Assumptions and limitations
- CLV = your decimal odds ÷ closing decimal odds − 1. Against the no-vig close, the closing price is first stripped of its margin by proportional normalization.
- Use the closing price from the same market (same side, line and period). A different line or a thin, slow market makes the comparison meaningless.
- The close is the market's last estimate, not the truth. Positive CLV on one bet proves little; judge it as an average over many bets.
- Nothing you enter is stored or sent anywhere.
What the closing line value calculator measures
Closing line value (CLV) compares the price you bet with the market's last price before the event starts. The Massachusetts Gaming Commission, which collected CLV data from sportsbooks, describes it as a measure of how "good" or "sharp" a player is, based on whether they bet at better odds than the odds at which the wager closes.[1]
The calculator gives two versions:
- CLV vs the raw close: your decimal odds ÷ the closing decimal odds − 1. Quick, but the closing price still includes the sportsbook's margin.
- CLV vs the no-vig close: first remove the margin from the closing market (you'll need the other side's closing price), then compare. If the close were the true price, this figure is also your bet's expected value.
Example
You bet at 2.20. The market closes at 2.00 on your side and 1.833 (-120) on the other.
| Value | |
|---|---|
| CLV vs raw close | 2.20 ÷ 2.00 − 1 = +10.0% |
| No-vig closing probability | 47.8% (fair odds 2.091) |
| CLV vs no-vig close | 2.20 ÷ 2.091 − 1 = +5.2% |
The raw figure flatters the bet because the closing price includes the margin. The no-vig figure is the fairer comparison.
Reading the result
One bet's CLV tells you very little; an average over many bets is a useful sign that you're betting before the market moves your way. It isn't proof of profit, because you still have to beat the sportsbook's margin. For the full explanation, including that caveat, read Closing line value (CLV) explained.
Frequently asked questions
How do you calculate closing line value?
Divide your decimal odds by the closing decimal odds and subtract 1. Betting 2.20 when the line closes at 2.00 is +10% against the raw close. Removing the closing margin first gives a fairer figure.
Is positive CLV the same as profit?
No. Positive CLV means you beat the market's final price, which is a good sign over many bets, but you still have to overcome the sportsbook's margin, and single results vary widely.
Why does the calculator need the other side's closing odds?
To remove the sportsbook's margin from the close. Without it, the comparison is against a price that still includes the vig, which flatters your CLV.
Sources
- 1.Player Limiting Data Analysis Results and Possible Next Steps (memo to the Commission, Sept. 30, 2025), Massachusetts Gaming CommissionRegulatory publication · accessed Oct 28, 2026
About this page
- Editorial review
- Approved by Owen Davids on Oct 30, 2026
- AI assistance
- Drafted with AI assistance. Facts, sources and conclusions were checked by a human editor before publication.
- Facts last checked
- Oct 30, 2026
How we research and label evidence: our methodology.
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