PredMark Calculator — Polymarket Odds, Kelly & EV Tools

⟳ Odds Converter

Polymarket Price

Enter the contract price as you see it on Polymarket (e.g. 0.55)

Implied Probability55.00%

Decimal Odds1.8182

American Odds-122

Bankroll ($)

Your True Probability (%)

Your honest estimate of the outcome's real probability

Polymarket Price

Kelly Fraction26.67%

Optimal Bet$2,667

Edge+10.00%

Polymarket Price

Your True Probability (%)

Decimal Odds1.8182

Expected Value (per $1)+$0.27

ROI+27.27%

Polymarket Price

At what true probability does this bet break even?

Breakeven Probability55.00%

You need the truth to be >55.00%

Decimal Odds Equivalent1.8182