Prediction Market Arbitrage Calculator
Calculate potential arbitrage profits between prediction market platforms. Enter Yes prices and fee rates to see if a risk-free spread exists.
Platform A (e.g. Polymarket)
Platform B (e.g. Kalshi)
How Arbitrage Works
Prediction market arbitrage occurs when the same event is priced differently across two platforms. If Platform A prices "Yes" at 55 cents and Platform B prices "Yes" at 48 cents, a trader can potentially profit from this discrepancy by buying on the cheaper platform and selling (or taking the opposite position) on the more expensive one.
The key to identifying true arbitrage is accounting for fees. Each platform charges transaction fees that eat into the spread. A raw 7-cent spread might become a 3-cent profit after fees, or might disappear entirely if fees are too high. This calculator factors in both platform fee rates to show you the net profit.
The spread is measured in basis points (bps), where 100 bps equals 1 cent. A spread of 200+ bps is generally considered actionable for cross-platform arbitrage, though execution speed and withdrawal times also affect real-world profitability.
Risk-free arbitrage requires simultaneous execution on both platforms. In practice, prices can move between the time you place orders, so many traders use automated systems or APIs to execute both legs as quickly as possible. PredRadar's real-time price tracking helps identify these opportunities the moment they appear.