Kalshi taker fee calculator (2026)
Kalshi charges takers 0.07 x P x (1 - P) per contract, peaking at 1.75c unrounded on a 50c contract. The published fee-schedule PDF has returned HTTP 429 since 2026-09-21, so the rate is documented, not independently verified. Kalshi rounds the fee on an order up to the next whole cent, which matters most on small tickets.
On $100 at 50¢ you pay $3.50 in fees on Kalshi
1.75¢ per contract · 200 contracts
On $100 at 50¢ you pay $2.50 in fees on Polymarket US
1.25¢ per contract · 200 contracts
Polymarket rate read from the catalog for sports_fees_v3 (13,936 markets in a sample of 20,000 rows drawn from 11,637,244 in the archive). Kalshi's rate is its published general schedule; the PDF has been rate-limiting fetches, so it is documented rather than verified.
Exchange-side taker fees per each venue's published formula (rate × contracts × price × (1 − price)); contracts = stake ÷ price, rounded down to whole contracts. Fees peak at 50¢ and shrink toward the extremes. Most quoted cross-venue “arbs” are negative-EV after these fees; the taker-fee breakeven on a Kalshi/Polymarket pair is roughly 3.5–4¢.
How does Kalshi's taker fee formula work?
Kalshi's published taker fee is 0.07 x P x (1 - P) per contract, where P is the contract's price in dollars (a 50c contract is P = 0.50). Makers pay 0.0. The 0.07 figure is Kalshi's general schedule rate, taken from kalshi.com/docs/kalshi-fee-schedule.pdf; a series can in principle carry its own fee multiplier, but TapeXray's archive has no multiplier table on file, so every Kalshi fee this site shows assumes a multiplier of 1.0 and states that basis as "general_schedule" rather than implying a series-specific number.
Because the formula is P x (1 - P), the fee is a curve, not a flat cent amount: it is largest at 50c and smallest near 0c or 100c. A 10c or 90c contract carries P x (1 - P) = 0.09, a third of the 0.25 value at 50c, so its unrounded per-contract fee is about a third of the peak. This page's table below prices that curve at five common points.
| Price | P x (1 - P) | Unrounded fee | Rounded-up fee (1 contract) |
|---|---|---|---|
| 10c | 0.09 | 0.63c | 1c |
| 25c | 0.1875 | 1.3125c | 2c |
| 50c | 0.25 | 1.75c | 2c |
| 75c | 0.1875 | 1.3125c | 2c |
| 90c | 0.09 | 0.63c | 1c |
Why does a single contract round up more than a big order?
Kalshi rounds the fee on an order up to the next whole cent, not the fee on each contract. A single 50c contract's unrounded fee is 1.75c, which rounds up to 2c: an 0.25c premium the trader pays only because a fee cannot be billed in a fraction of a cent. A 200-contract order at 50c has an unrounded total of 350c exactly, so it rounds to $3.50 with no premium at all, because 350 is already a whole number of cents. The one-cent rounding cost is proportionally largest on the smallest tickets and disappears as an order grows.
That rounding step is also where a float-noise bug lived until 2026-09-23. Computing 0.07 x 200 x 0.5 x 0.5 x 100 in ordinary floating-point arithmetic does not land on exactly 350; it lands about six-millionths of a cent above it, and rounding that noise up bought a whole extra cent, $3.51 instead of $3.50. The fix clears six decimal places of noise before applying the ceiling, which is far finer than any fee Kalshi actually charges.
What does Kalshi charge on a full-dollar order?
A 200-contract order at 50c is the canonical example because 50c is where the per-contract fee peaks, but the same order-level formula applies at any price. A $100 stake buys more contracts the further the price sits from 50c: 1,000 contracts at 10c, 200 at 50c, or about 111 at 90c, and the fee shrinks along with the P x (1 - P) curve at each of those prices, not just with the smaller per-contract dollar amount.
| Stake | Price | Contracts | Kalshi fee |
|---|---|---|---|
| $100 | 50c | 200 | $3.50 |
| $50 | 50c | 100 | $1.75 |
| $200 | 50c | 400 | $7.00 |
For a Polymarket comparison at these same stakes, see the Polymarket fee page; for the live gap board these fees feed into, see the board. None of these figures change by state or account type; Kalshi's published schedule applies the same 0.07 rate everywhere it operates.