For informational & educational purposes only. Not financial advice. No guarantee of outcomes. Users are responsible for compliance with local laws. 18+. Read full disclaimer →
All calculators
Free Tool

Expected Value (EV) Calculator

Translate a probability + price into expected value per dollar staked. Positive EV = the math says you have an edge.

EV per $
+$0.0920
EV (dollar)
+$9.20
Market implied prob
47.6%
Your edge
+4.4%

The EV formula

EV per $1 = p × (decimal_odds − 1) − (1 − p)

where p = your estimated probability of winning

If EV per $1 is positive, the bet has long-run expected profit at that price — assuming your p is correct. Variance still applies; the bet can lose any individual time.

Pair this with the Kelly calculator to size the position.

Free weekly email
Sunday Whale Report — top consensus moves of the week.
Free. Unsubscribe in 1 click. See verified call history →
Compliance & Disclosures

PolySharks.ai is a market-intelligence and analytics platform operated by 8eight8 LLC. The site is provided for informational and educational purposes only — it is not financial, legal, tax, or gambling advice. Past whale performance and historical data carry no guarantee of future outcomes. Trading prediction markets involves substantial risk of loss, including 100% of principal. Users are solely responsible for compliance with the laws of their local jurisdiction — prediction-market access is restricted or prohibited in some US states and countries; verify legality before depositing or trading on Polymarket or Kalshi. PolySharks does not custody funds and is not affiliated with Polymarket Inc. or Kalshi Inc. 18+ only (21+ in some jurisdictions).