Results
| Outcome | Entered Odds | Decimal Odds | Raw Probability | No-Vig Probability | Fair Decimal |
|---|
| Metric | Value |
|---|
Calculator Inputs
Example Data Table
| Outcome | Market Odds | Decimal Odds | Raw Probability | No-Vig Probability |
|---|---|---|---|---|
| Home Win | -145 | 1.6897 | 59.18% | 56.67% |
| Draw | +290 | 3.9000 | 25.64% | 24.55% |
| Away Win | +410 | 5.1000 | 19.61% | 18.78% |
Formula Used
For positive odds: Probability = 100 / (Odds + 100)
For negative odds: Probability = |Odds| / (|Odds| + 100)
Probability = 1 / Decimal Odds
Decimal Odds = (Numerator / Denominator) + 1
Overround = Sum of all raw implied probabilities
No-Vig Probability = Raw Probability / Overround
Fair Decimal Odds = 1 / No-Vig Probability
Net Profit = Stake × (Decimal Odds − 1)
Total Return = Stake × Decimal Odds
EV = (Model Probability × Net Profit) − ((1 − Model Probability) × Stake)
Kelly Fraction = ((b × p) − q) / b, where b = Decimal Odds − 1
How to Use This Calculator
- Choose your market odds format: American, decimal, or fractional.
- Enter the name and odds for the outcome you want to evaluate.
- Add at least one competing outcome to remove vig accurately.
- Enter your stake amount to estimate profit, return, and value.
- Add your model probability for Outcome 1 to calculate edge and EV.
- Enter bankroll and Kelly mode to generate a suggested stake size.
- Press Calculate Probability to show results above the form and render the Plotly chart.
Frequently Asked Questions
What is implied probability in betting?
Implied probability converts odds into an estimated chance of winning. It helps you compare market prices, identify value, and understand how likely a sportsbook believes an outcome is.
Why should I remove vig from market odds?
Sportsbooks build margin into prices. Removing vig normalizes the market so the probabilities add to 100%, giving you a cleaner estimate of fair odds.
Can I use American, decimal, and fractional odds here?
Yes. Select one odds format, enter the lines, and the calculator converts them into decimal odds for all probability, payout, and value calculations.
Why is no-vig probability unavailable with one line?
No-vig probability needs a market to normalize. Enter at least two outcomes so the calculator can measure overround and remove bookmaker margin properly.
What does positive expected value mean?
Positive expected value means your model probability suggests the wager should earn money over many similar bets, even though single bets can still lose.
How is Kelly staking used here?
Kelly staking sizes a bet from your edge and odds. This calculator shows full, half, or quarter Kelly suggestions when bankroll and model probability are entered.
Can I analyze three-way sports markets?
Yes. You can enter up to three outcomes, making the tool useful for soccer match result markets and similar three-way pricing structures.
Is this calculator a prediction system?
No. It evaluates prices, probabilities, and value. You still need your own research or model to estimate true win probability before betting.