Tools
Free, educational calculators. Outcomes are uncertain; no guarantees. Always follow local laws.
Implied Probability & Odds Converter Basics
Tip: Decimal → implied% = 100 / decimal. American +150 ⇒ 2.50; −120 ⇒ 1.833…
Expected Value (EV) Long-run
EV = p × (odds − 1) − (1 − p). Positive EV doesn’t mean guaranteed wins.
Kelly Criterion Risk
Kelly full = (bp − q)/b where b = (odds−1), p = win prob, q = 1−p. Many use 0.25–0.50 (fractional Kelly).
Parlay / Accumulator Multi-leg
Total decimal = product of legs. Implied% = 100 / total.
Bookmaker Margin (Overround) 1X2
Margin = (Σ(100/odds)) − 100. Lower margin is generally better for bettors.
Educational use only; nothing here is financial advice. No guaranteed results.