Kalshi fees explained
Kalshi charges an explicit, visible fee on a trade — and its shape catches people out, because it is largest exactly where most trading happens.
Key takeaways
- Kalshi's trading fee is a curve, not a flat percentage: largest around 50¢ and small near 0¢ and 100¢.
- Whether you trade as taker or maker is decided by your order type, and cancelling an unfilled order costs nothing.
- On the thinly traded majority of markets the bid-ask spread costs more than the fee — compare depth before comparing fee tables.
The fee is a curve, not a percentage
The instinct from every other financial product is that a fee is a flat percentage of the amount traded. On a prediction market it is not, and the reason is structural: the exchange is not charging you for the size of the trade, it is charging you for the risk it takes on in matching it.
The result is a curve that peaks around the middle of the price range and shrinks towards both ends. A contract at 50¢ carries the most fee per contract; one at 5¢ or 95¢ carries very little. That is the opposite of what most people assume, and it matters because the middle of the range is where the interesting markets live.
Fee schedules change. Any specific figure — including any you read here — is a snapshot. The live schedule at the exchange is the only authority.
Taker, maker, and the order type that decides which you are
If you send an order that executes immediately against what is already on the book, you are the taker and you pay the fee. If you post a limit order away from the current price and someone else trades against it later, you are the maker.
That distinction is entirely under your control, and it is the single largest lever on your cost. The trade-off is real: a limit order can sit unfilled while the price moves away from you. Paying the taker fee is buying immediacy, and immediacy is sometimes worth it.
- Market order, or a limit order priced to cross: you are the taker.
- Limit order that rests on the book and is filled later: you are the maker.
- Cancelling before a fill costs nothing — an unfilled order is not a trade.
Settlement is a second, separate event
A contract you hold to the end settles automatically at $1 or $0. Exchanges have at times charged separately at settlement, and whether they do is a schedule question rather than a structural one — check it, because it changes the arithmetic on a position you intend to hold rather than trade out of.
This is one of the places where holding and trading genuinely differ in cost. If you plan to exit before resolution, the fee you care about is the one on the exit trade; if you plan to hold, it is the settlement treatment.
What we see in the data: the spread usually costs more
Our market cache tracked 43,914 markets across both venues as of 1 September 2026, of which 6,360 were open and active. Across that inventory the pattern is consistent and worth more than any fee table: on the thinly traded majority, the gap between the best bid and the best ask is a larger cost than the explicit fee.
A market quoted 30¢ / 36¢ costs you six points of implied probability the moment you cross it. On a contract in that price region, that is several times the trading fee. People optimise the number the exchange prints and ignore the one it does not — and the second one is bigger.
The practical rule that follows: before comparing venues on fees, compare them on depth at the price you actually want. A venue with a marginally higher fee and a tighter book is cheaper. Our comparison of the major prediction market apps puts the venues side by side.
| Cost | Visible? | Who controls it |
|---|---|---|
| Trading fee | Yes — printed by the exchange | You, via order type |
| Bid-ask spread | Only if you look at the book | You, via patience |
| Settlement treatment | In the schedule | The exchange |
| Capital tied up until resolution | No | You, via holding period |
Comparing against a sportsbook
A sportsbook does not show you a fee. It builds its margin into the line, which is why the implied probabilities of both sides of a book's market add up to more than 100 %. An exchange quotes a price that is close to the market's honest probability and charges its fee openly on top.
That makes the two look very different and behave more similarly than the presentation suggests. The honest comparison is total cost per unit of exposure, not fee versus no fee — and to run it you need the book's overround, which the book does not print either.
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Primary sources
How this was researched
Guides are written against primary sources and checked against the market data we collect ourselves.
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Open the payout calculatorFrequently asked questions
- Does Kalshi charge fees?
- Yes, and unlike a sportsbook it shows them. The trading fee depends on the price and the number of contracts rather than being a flat percentage, and it is largest around the middle of the price range.
- Why is the fee highest at 50 cents?
- Because the fee tracks the risk the exchange takes on in matching the trade, and that risk peaks where the outcome is most uncertain. Towards 0¢ or 100¢ the contract is close to decided and the fee shrinks accordingly.
- How do I pay less?
- Post limit orders instead of crossing the spread, and trade markets with real depth. On thin markets the spread costs more than the fee, so the venue with the tighter book is usually the cheaper one regardless of its schedule.
- Are Kalshi fees higher than Polymarket's?
- Both use a price-dependent shape rather than a flat percentage, and both revise their schedules. Comparing the two on a single published number is unreliable — compare the total cost on the specific market you want, spread included.
Keep learning
Prediction markets carry real risk of loss. Nothing on Market Guy is financial advice — it is research tooling to help you think, not a signal to trade.