PREDICTION MARKET TOOLS
Free prediction market calculators and tools
Estimate profit, convert odds, find useful tools and track your forecasts.
Make your next step clearer
Polymarket & Kalshi Profit and Payout Calculator →
Calculate prediction-market payouts, fees, net profit, ROI and break-even for settlement or an early sale.
Prediction Market Odds Converter →
Convert probability, contract price, decimal odds and American odds. See what a quoted price means before fees.
Find the Right Prediction Market Tool →
Match your platform, workflow, budget and preferred interface with tools whose support has been checked.
Prediction Calibration Journal →
Record your forecasts locally, resolve questions and measure your Brier score without an account.
No account required. Calculations run in your browser. Shared calculator links contain the scenario values you choose to share; the calibration journal stays in local browser storage.