Step-by-step tutorials for using Market Math calculators on specific platforms. Each guide includes an embedded calculator, worked examples with real-looking numbers, and platform-specific pro tips.
Kalshi
Calculate exact Kalshi fees for any contract price. Compare taker vs maker fees and find your true break-even.
Polymarket Fee Calculator — Global vs US Fees ComparedPolymarket
Calculate Polymarket fees for Global (2% on winnings) and US (0.1% taker) versions.
Robinhood Event Contract Fees ExplainedRobinhood
Calculate Robinhood's flat $0.01-$0.02 per contract fee and compare to other platforms.
DraftKings Predictions Fee CalculatorDraftKings
Calculate DraftKings event contract fees — $0.02 per contract per side via CME Group.
ForecastEx (Interactive Brokers) Fee CalculatorForecastEx
Calculate ForecastEx's $0.01 per contract fee — the lowest in the prediction market industry.
PredictIt Fee Calculator — Profit Tax & Withdrawal FeesPredictIt
Calculate PredictIt's 10% profit fee plus 5% withdrawal fee and see why the total cost is the highest in the market.
Kalshi
Find the minimum win rate you need on Kalshi after accounting for taker and maker fees.
Polymarket Break-Even CalculatorPolymarket
Calculate the minimum win rate needed to profit on Polymarket Global and US.
Robinhood Event Contracts Break-Even CalculatorRobinhood
Calculate the minimum win rate on Robinhood event contracts after the flat per-contract fee.
DraftKings Predictions Break-Even CalculatorDraftKings
Find the win rate you need on DraftKings event contracts after $0.02/contract fees.
Kalshi
Calculate expected value and Kelly bet sizing for Kalshi contracts, including taker and maker fee adjustments.
Polymarket Expected Value CalculatorPolymarket
Calculate EV and optimal sizing for Polymarket positions, accounting for the 2% profit fee.
Robinhood Event Contracts EV CalculatorRobinhood
Calculate expected value for Robinhood event contracts including the flat per-contract fee.
DraftKings
Convert DraftKings American odds to decimal, fractional, and implied probability. Understand what your DraftKings lines really mean.
FanDuel Odds Converter — Convert Any FanDuel LineFanDuel
Convert FanDuel American odds to decimal, fractional, and implied probability. Compare FanDuel lines across formats.
Kalshi
Find risk-free arbitrage opportunities between Kalshi and other prediction markets. Calculate stakes and guaranteed profit after fees.
Cross-Platform Arbitrage with PolymarketPolymarket
Find and calculate arbitrage between Polymarket and other prediction markets. Account for Polymarket's unique fee structure.