Kalshi’s fee is small, invisible, and it is quietly the largest single line item in most traders’ year. It is invisible because the exchange nets it out before you ever see a balance, so you have never been handed the invoice. And it is larger than it looks because of where it sits: the fee rides on top of your entry price, which means your real breakeven is never the price on the screen.
The good news is the important half: on standard markets, the fee only applies when you cross the spread. Rest an order on the book and let someone else fill it, and you pay nothing. The fee is not a tax on trading. It is a tax on impatience.
Holding to settlement pays the taker fee once, because settlement is free. Trading back out pays it twice, once each way.
Crossing the spread costs you $800.00 a year. Resting your orders costs $0.
FEE PER CONTRACT
4¢
both ways at 50¢
YOUR REAL BREAKEVEN
54¢
not the 50¢ on the screen
EXTRA WINS NEEDED
+4.0
per 100 trades, just to match a maker
KEPT OVER 200 TRADES
+$800.00
by resting instead of crossing
Here is the part that gets people. A taker buying at 50¢ does not break even when the market is worth 50¢. They break even at 54¢, because the fee rides on top of the price. So they need to be right 54.0% of the time where a maker needs 50.0%. Two traders, identical reads, identical markets, and one of them is quietly 4.0 points of win rate behind before either of them has been right about anything.
Where the fee bites hardest
Kalshi’s taker fee is not a flat percentage. It scales with the uncertainty of the contract, peaking at 50¢ and shrinking toward both extremes. Coin flips are the most expensive thing on the exchange, and heavy favourites are the cheapest, which is the opposite of most people’s intuition.
1¢25¢50¢ (most expensive)75¢99¢
The fee formula is roughly 7% × price × (1 - price) per contract, rounded up to the cent. At 50¢ that is 2¢. At 90¢ it is 1¢. Confirm the current schedule against Kalshi’s fee page before you build a strategy on it.
Your real breakeven at every price
Taking a contract at the price in the left column, holding to settlement (one fee). The right column is what the market must genuinely be worth for you to make a single penny.
You pay
Taker fee
True breakeven
Win rate needed
Maker needs
10¢
1¢
11¢
11%
10% (1 pts less)
20¢
2¢
22¢
22%
20% (2 pts less)
30¢
2¢
32¢
32%
30% (2 pts less)
40¢
2¢
42¢
42%
40% (2 pts less)
50¢
2¢
52¢
52%
50% (2 pts less)
60¢
2¢
62¢
62%
60% (2 pts less)
70¢
2¢
72¢
72%
70% (2 pts less)
80¢
2¢
82¢
82%
80% (2 pts less)
90¢
1¢
91¢
91%
90% (1 pts less)
95¢
1¢
96¢
96%
95% (1 pts less)
Trading back out instead of holding doubles the fee, and therefore doubles every gap in this table. That is why frequent in-and-out trading on coin-flip markets is the single most expensive habit on the exchange, and why the same trader can have a genuinely good read and still finish the year down.
What did fees actually take from you?
The simulator above is the general case. The specific case is in your own trade history, and it is usually worse than people guess. Upload your Kalshi CSV to the free Trade Report and the True Cost Machine tells you exactly what share of everything you won went to fees, what your true average breakeven is, which categories leak the most, and whether fees are the reason a winning year finished flat. It runs in your browser; nothing is uploaded.
Fees are only half the cost. The spread is the other half, and it varies enormously by category: we measure the real round-trip cost of every live Kalshi market so you know where trading is cheap and where it quietly is not. Fee figures here follow Kalshi’s published taker formula; confirm the current schedule on their fee page before building a strategy on it. Educational, not financial advice.
So what does the fee cost on the trade you are actually looking at? Run the numbers on one: