EV Calculator
Compare your bookmaker odds against the fair line. See +EV %, expected dollar profit and the Kelly-suggested stake.
How the EV calculator works
The fair odds represent the true probability of an outcome. If your bookmaker is offering better odds than fair, the bet has positive expected value (+EV). Over a long sample of similar bets, +EV wagers produce profit.
Formula: EV = (p × (odds − 1) × stake) − ((1 − p) × stake), where p = 1 / fair odds.
Kelly criterion
Kelly suggests the optimal stake as a percentage of bankroll. We show full, half and quarter Kelly — most punters use quarter Kelly to handle estimation error and reduce variance.
FAQ
- What is expected value (EV) in sports betting?
Expected value is the average profit or loss a bet would produce if repeated many times. A positive EV (+EV) bet has long-term profit potential; a negative EV bet is statistically a losing wager.
- How do I find fair odds?
Fair odds (or no-vig odds) are typically derived from sharp markets — the international sharp baseline, the Betfair Exchange, or by removing the bookmaker margin from a market. Krok Odds calculates these automatically from the sharpest available line.
- Should I use full Kelly staking?
Most professional bettors use fractional Kelly (typically quarter or half) because estimates of true probability are imperfect. Full Kelly maximises growth assuming your edge is exact — quarter Kelly is safer for real-world variance.
- How much edge is realistic?
Sustainable long-term edges sit between 1% and 5% per bet. Anything claiming 20%+ EV regularly is either using a stale line or measuring against a poor fair-odds estimate.
Want this automated across 100+ bookmakers?
Krok Odds scans Sportsbet, TAB, Ladbrokes, Bet365, Neds, PointsBet AU and more — surfaces every arb, +EV, middle and low-hold in real time. 7-day Apex trial, card required.