Arbitrage Calculator
Enter YES and NO prices for the same event across Polymarket and Kalshi.
Assumes ~1% Polymarket taker fee + ~1% Kalshi transaction fee. Net edge only — actual profit depends on fill prices and slippage. Not financial advice.
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Enter the best ask price for the YES side on one platform (e.g. Polymarket) and the best ask price for the NO side on the other platform (e.g. Kalshi) for the same real-world event. The calculator instantly shows whether a profitable arbitrage opportunity exists after accounting for typical platform fees.
Gross spread is the raw gap between $1.00 (the guaranteed settlement value of any binary contract) and your combined cost. A positive gross spread means the market is theoretically mispriced. Net edge after fees deducts estimated platform fees (~1% per leg) to give you the realistic profit available.
Profit per $100 shows the expected dollar return if you deploy $100 across both legs at the quoted prices. This assumes full fills at the quoted price — actual returns will vary based on order book depth and slippage.
What makes an arbitrage opportunity valid?
A valid opportunity requires that the combined cost of YES and NO for the same event across two platforms is below $1.00 after fees. On Polymarket and Kalshi, the same binary event is often priced differently because the platforms have independent liquidity pools and different user bases. These price gaps typically last 10–60 seconds before market makers correct them.
Typical profitable spreads range from 1.5% to 4% gross. After fees, net edges of 0.5%–3% are realistic on active markets. Larger spreads appear during breaking news events, elections, and major economic data releases. See the full arbitrage guide for more detail.
Learn more about prediction market arbitrage:
© 2026 Arbitrage Agent. Not financial advice. Trading involves risk of loss.