Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Your estimated P(over)
59.9%
Your estimated P(under)
40.1%
EV betting the over
$11.93
EV betting the under
-$21.65
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter posted win total line.
- 2Enter over odds (american).
- 3Enter under odds (american).
- 4Enter your projected win total.
- 5Enter stake ($).
- 6Read your your estimated p(over) on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Preseason win total markets (e.g., a team's win total set at 8.5 games with over/under prices) are priced from a projected mean number of wins, converted into a probability distribution, then quoted as two-way odds with vig. This calculator estimates the implied probability of the over and under from the posted odds, compares it against your own projected win total (using a simple normal approximation around the number of games), and computes expected value for whichever side you think is mispriced. Win total markets move slowly over an entire season and are especially sensitive to key injury news, coaching changes, and offseason roster turnover that happens after the number is initially posted — lines set in May often look very different by the September opener. This tool assumes a roughly normal distribution of win outcomes around your projected mean, which is a reasonable approximation for most sports but breaks down for teams with unusually bimodal outcomes (e.g., a team that either tanks hard or unexpectedly contends with no in-between).
Worked example
Using the values the calculator loads with:
Inputs
- Posted win total line: 8.5
- Over odds (American): -115
- Under odds (American): -105
- Your projected win total: 9.5
- Stake: 100 $
Results
- Your estimated P(over): 59.9%
- Your estimated P(under): 40.1%
- EV betting the over: $11.93
- EV betting the under: -$21.65
What each field means
Inputs
- Posted win total line
- The posted win total line used in the calculation. Starts at 8.5 so you have a working example on load. Accepted range: 0–20.
- Over odds (American)
- The over odds (american) used in the calculation. Starts at -115 so you have a working example on load.
- Under odds (American)
- The under odds (american) used in the calculation. Starts at -105 so you have a working example on load.
- Your projected win total
- The your projected win total used in the calculation. Starts at 9.5 so you have a working example on load. Accepted range: 0–20.
- Stake ($)
- The stake used in the calculation, measured in $. Starts at 100 $ so you have a working example on load.
Results
- Your estimated P(over)
- Returned as a percentage and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Your estimated P(under)
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- EV betting the over
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- EV betting the under
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why use 2.0 wins as the standard deviation?
It's a commonly used approximation for NFL season win totals based on historical variance in team win-loss records; other sports and team profiles vary. A rebuilding team with a rookie quarterback and a defending contender both nominally have season-long uncertainty, but their actual outcome distributions differ, so treat this sigma as a reasonable default, not a precise fit for every team.
Why would a line set in May be wrong by September?
Injuries, holdouts, coaching staff turnover, and roster changes all happen after win totals are initially posted, and books are often slower to move preseason futures than game lines because there's less liquidity and less frequent new information forcing a repricing. A star player suffering a training camp injury after the number is set is the classic case where the market probability lags reality.
Is my own projection likely to be better than the sportsbook's number?
For most bettors, no — books' win total lines are set using extensive modeling and are historically quite sharp on average. This tool is useful when you have specific information the market may be underweighting (a confirmed depth chart change, a schedule strength quirk, or a coaching change), not as a way to beat the market on general vibes about a team.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Related tools
Expected Value (EV) Bet Calculator
Find the dollar EV of a wager given your true win probability.
Futures Bet Hold Calculator
See how much total vig a futures board (all teams/players) is holding.
Closing Line Value (CLV) Calculator
Measure whether you beat the market's final price, independent of the result.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Season Win Total EV Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/season-win-total-ev-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/season-win-total-ev-calculator" target="_blank" rel="noopener">Season Win Total EV Calculator — RevenueLab</a> (2026).</p>
Source: [Season Win Total EV Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/season-win-total-ev-calculator) (2026).