Kalshi fees explained
Kalshi charges a trading fee of 0.07 × contracts × P × (1 − P), rounded up to the next cent, where P is the contract price in dollars. It is charged only on the side that fills, and there is no fee when a contract settles. At 50¢ that is $1.75 per 100 contracts; at 10¢ or 90¢ it is $0.63. The fee is largest near 50¢ because P × (1 − P) peaks there.
Kalshi fee table
Taker fee for an order of 100 contracts on a standard series. "Share of cost" is the fee as a percentage of what the contracts cost you, which is why cheap contracts are proportionally the most expensive to trade.
| Price | Fee per 100 contracts | Per contract | Share of cost |
|---|---|---|---|
| 5¢ | $0.34 | 0.34¢ | 6.8% |
| 10¢ | $0.63 | 0.63¢ | 6.3% |
| 20¢ | $1.12 | 1.12¢ | 5.6% |
| 30¢ | $1.47 | 1.47¢ | 4.9% |
| 40¢ | $1.68 | 1.68¢ | 4.2% |
| 50¢ | $1.75 | 1.75¢ | 3.5% |
| 60¢ | $1.68 | 1.68¢ | 2.8% |
| 70¢ | $1.47 | 1.47¢ | 2.1% |
| 80¢ | $1.12 | 1.12¢ | 1.4% |
| 90¢ | $0.63 | 0.63¢ | 0.7% |
| 95¢ | $0.34 | 0.34¢ | 0.4% |
Kalshi fee calculator
Maker fees, fee-free series and other charges
Resting a limit order that someone else fills makes you the maker. On most Kalshi series makers pay nothing; on a short list of designated series they pay 0.0175 × contracts × P × (1 − P), a quarter of the taker rate. The fee multiplier is set per series: of 13,839 series we track, 19 charge half the standard fee and 14 charge nothing. Deposit and withdrawal charges are separate from trading fees and depend on the payment method, so check Kalshi's current fee schedule before moving money.
Kalshi vs Polymarket fees
Polymarket publishes a fee schedule per market. Where fees are enabled, takers pay a rate of 3–5% depending on category on the same P × (1 − P) curve; part of the book has fees disabled entirely, and makers pay nothing and earn a rebate. On 100 contracts at 50¢ that is $0.75–$1.25 on Polymarket when fees are on, $0 when they are off, against $1.75 on Kalshi. Polymarket's other cost is the bid-ask spread you cross, which on thin markets can be larger than either venue's fee.
Measured on the pairs currently on our board:
| Venue | n | Average fee per contract | Edge given up |
|---|---|---|---|
| kalshi | 13 | 1.38¢ | 1.97pp |
| polymarket | 8 | 0.79¢ | 4.79pp |
Fees by price band, measured live
| Contract price | n | Average fee per contract | Edge given up |
|---|---|---|---|
| under 20¢ | 2 | 0.72¢ | 1.00pp |
| 20–40¢ | 2 | 1.36¢ | 4.12pp |
| 40–60¢ | 14 | 1.24¢ | 3.42pp |
| 60–80¢ | 1 | 1.41¢ | 3.41pp |
| over 80¢ | 2 | 0.66¢ | 1.16pp |
Small samples, so read the n column before drawing a conclusion from any single band. The shape is structural rather than statistical: a fee proportional to P × (1 − P) is largest where the contract is most uncertain.
Why fees decide most cross-venue trades
A 2¢ gap between Kalshi and Polymarket looks like free money. Buying both sides at 50¢ costs about 1.75¢ in Kalshi fees plus up to 1.25¢ on Polymarket, so the gap is gone before slippage. That is the most common reason a spread that looks free is not, and it is why every number on the arbitrage page and in the scanner is shown twice: before fees and after.
Common questions
How much does Kalshi charge per trade?
0.07 × contracts × price × (1 − price), rounded up to the cent, on the filled side. The most it can be is 1.75¢ per contract, at a price of 50¢.
Does Kalshi take a cut of winnings?
No. The fee is charged when your order fills, not when the contract settles, so a winning contract pays the full $1.
Are Kalshi limit orders free?
On most series, yes, if your resting order is filled by someone else. A short list of designated series charges makers 0.0175 × contracts × P × (1 − P).
Is Polymarket cheaper than Kalshi?
Usually, on fees alone: Polymarket's taker rates are 3–5% on the same curve against Kalshi's 7%, and part of its book is fee-free. Total cost also depends on the spread, which is often wider on thinly traded Polymarket markets.