Polymarket Fees Calculator

On Polymarket, a taker is someone who places a market order that immediately matches an existing limit order in the order book. Takers pay a fee; makers (who post limit orders and add liquidity) pay nothing. If you're buying or selling at the current market price, you're most likely a taker. The fee applies to both buy and sell orders — any time you take liquidity, you pay it.

The formula is fee = C × feeRate × p × (1 − p), where C is the number of shares, feeRate is the category rate, and p is the share price in dollars (e.g. 50¢ = 0.50). The p × (1 − p) term makes fees symmetric around 50¢ and causes them to approach zero near 0¢ or 100¢, reflecting lower uncertainty at the extremes.

Place limit orders instead of market orders. A limit order rests in the order book until someone else matches it — making you the maker, not the taker. You set your desired price and wait. The trade-off is that your order may not fill immediately or at all if the market moves away from your price.

Polymarket sets the fee rate per market, not just per category. Pasting the event URL lets this calculator fetch the exact fee rate for that specific market from the Polymarket API, so your estimate is precise rather than based on a category approximation.