Enter a contract price and we’ll compute effective post‑fee prices for Kalshi, PredictIt, and Polymarket. Prices are per $1 payoff (use 0.60 for 60%).
Kalshi (Taker)
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Kalshi (Maker)
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PredictIt
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Polymarket
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Always check official fee schedules and your own execution costs - trade at your own risk!
Frequently Asked Questions
This tool adjusts contract prices from Kalshi, PredictIt, and Polymarket to account for their different fee structures. That way, you can compare markets on an equal footing and spot true arbitrage opportunities that fees might otherwise hide.
Because each exchange charges fees differently:
Kalshi: per-order trading fees (taker/maker) based on price × contracts × (1 − price), rounded up to the cent.
PredictIt: 10% fee on profits plus a 5% withdrawal fee.
Polymarket: 0% trading fee.
A contract at 60¢ doesn’t mean the same thing across platforms. After fees, the “effective” probability could be:
Taker = you cross the spread and fill immediately. Higher fee (7%).
Maker = your order rests and someone else fills it. Lower fee (1.75%). The calculator shows both prices so you can see the difference.
Because fees stack: 10% on profits, then 5% on withdrawals. For a 60¢ entry the effective price is about 65.9¢ using this calculator’s formula (p / [1 − 0.10 × (1 − p) − 0.05]).
Compare the fee-normalized prices, not the raw market prices. If Kalshi’s normalized price is 61¢ and Polymarket’s is 63¢, there might be an arbitrage if liquidity is good.