Free Arbitrage Tools

Calculators for Polymarket and Kalshi arbitrage. No sign-up needed.

Arbitrage calculator →YES and NO prices, stake and days to resolution: cost, Kalshi fee, net edge and annualised return.Kalshi fee calculator →Taker fee for an order using 0.07 × C × P × (1 − P), rounded up to the cent, with a table by price.Annualised return calculator →Turn a profit earned over weeks or months into a simple and compounded yearly rate.Quick spread calculator →Enter a YES and a NO price to see the gross spread and the net edge after fees.Hedge & arbitrage sizing →Size a two-leg arbitrage from a budget, or hedge a position you already hold.No-vig calculator →Remove the margin from odds to get fair probabilities.Kalshi fair odds calculator →Fair probability and break-even after Kalshi's taker fee.

Arbitrage Agent matches markets across Kalshi and Polymarket and shows them in a live feed with a step-by-step guide for both legs. You place the orders yourself.

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