Free tools
Kelly calculator
Work out how much of your bankroll an edge is worth, then check a price against its no-vig fair odds. Runs in your browser; nothing you type is sent anywhere.
Kelly bet size calculator
Recommended stake
$11.67
1.17% of bankroll, to win $14.00
- Implied probability (the price)
- 45.45%
- Your win probability
- 48.00%
- Edge (yours minus implied)
- +2.55% pts
- EV per $1 staked
- +$0.056
- Full Kelly
- 4.67%
Kelly: stake = bankroll × (b·p − q) ÷ b, where b is the net payout per $1, p is your win probability and q = 1 − p. The answer is only as good as p. If your estimate is too high, Kelly will over-bet; many bettors use a fraction of Kelly for that reason. This is an educational calculator, not financial advice.
No-vig fair odds calculator
Enter both sides of a two-way market (a spread, total or moneyline) to remove the book's margin.
American odds, 100 or more on either sign. Example: -110 and -110.
| Side A | Side B | |
|---|---|---|
| Offered odds | −120 | +100 |
| Implied probability | 54.55% | 50.00% |
| Fair probability | 52.17% | 47.83% |
| Fair odds | −109 | +109 |
Book margin (vig): 4.55%
Method: fair probability = side's implied probability ÷ (sum of both sides' implied probabilities). If another book offers a side at better odds than its fair odds, that price is +EV on this estimate.
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