Use real market inputs
Enter the odds you actually see and a probability estimate you can defend.
Professional calculators.
No marketing arithmetic.
Use the tools below to check expected value, fractional Kelly sizing, no-vig probability and odds conversion with your own inputs.
Expected Value Calculator
Enter the offered decimal odds and your estimated probability of winning.
Formula
EV% = (p × decimal odds) − 1Kelly Criterion Calculator
Estimate a bankroll stake using fractional Kelly. Fractional Kelly reduces volatility compared with full Kelly.
Formula
f* = (b × p − q) / bNo-Vig Calculator
Remove the bookmaker margin from a two-way market using proportional normalization.
Method
fair p = implied p / total implied pOdds & Payout Calculator
Convert decimal odds to implied probability and estimate total payout and net profit.
Formula
payout = stake × decimal oddsHOW TO USE THESE TOOLS
Calculator first. Explanation second.
Separate edge from stake size
Expected value tells you whether a price is attractive; Kelly helps decide how much bankroll to risk.
Account for bookmaker margin
For market-derived probabilities, remove the vig before treating the implied percentage as fair.