What each venue charges per contract, from our checked fee data.
A taker pays at most 1.75¢ per contract on Kalshi, 1.74¢ on Polymarket US and 1¢ on Polymarket's offshore politics markets. On all three the fee is largest on a contract priced at 50 cents and shrinks towards zero as the price nears 0 or 100 cents. Kalshi charges makers on 101 of 4,200 open series; Polymarket never charges makers, and pays them a rebate on both its exchanges.
Every figure read from the venue's own published schedule on 2 October 2026. Polymarket US schedule effective 1 October 2026.
Each venue multiplies a coefficient by the number of contracts, the price, and one minus the price: fee = coefficient × contracts × price × (1 − price). Price times one minus price is largest at 50 cents, where it equals 0.25, so the most any one contract can cost is the coefficient times 25 cents. A coefficient of 0.07 is not a percentage: it is the number in that formula.
| Kalshi | Polymarket US | Polymarket (offshore) | |
|---|---|---|---|
| Applies to | Standard series; some series use a multiplier | All standard trades; the schedule publishes no per-category rates | Politics (other categories below) |
| Taker coefficient | 0.07 | 0.0695 | 0.04 |
| Most per contract (at 50¢) | 1.75¢ | 1.74¢ | 1¢ |
| Makers | Charged on 101 of 4,200 open series, not on the rest | Receive a rebate (rebate coefficient 0.0125) | Never charged; receive rebates of 15% to 25% depending on category |
| Fee-free | 11 individually fee-free series | None; the schedule lists no fee-free markets | Geopolitics (the whole category) |
| Rounding | Rounded up | To the nearest cent; an exact half rounds to the even cent | To 5 decimal places; anything below 0.00001 USDC is not charged |
| Source | Fee schedule (PDF), Series (API), Fee changes (API), Fee rounding, read 2 October 2026 | Fee schedule, read 2 October 2026 | Fee schedule, read 2 October 2026 |
Polymarket's offshore exchange sets a different coefficient for each category. Geopolitics carries none.
| Category | Coefficient | Most per contract |
|---|---|---|
| Crypto | 0.07 | 1.75¢ |
| Culture | 0.05 | 1.25¢ |
| Economics | 0.05 | 1.25¢ |
| Other | 0.05 | 1.25¢ |
| Sports | 0.05 | 1.25¢ |
| Weather | 0.05 | 1.25¢ |
| Finance | 0.04 | 1¢ |
| Mentions | 0.04 | 1¢ |
| Politics | 0.04 | 1¢ |
| Tech | 0.04 | 1¢ |
| Geopolitics | 0 | No fee |
Illustrative only: 100 contracts bought as a taker, at two prices, using the coefficients above and the offshore politics rate.
| Price | Kalshi | Polymarket US | Polymarket (offshore), politics |
|---|---|---|---|
| 50¢ | $1.75 | $1.74 | $1.00 |
| 90¢ | $0.63 | $0.63 | $0.36 |
Polymarket US rounds to the nearest cent, with exact halves rounded to the even cent, as its schedule states: at 50 cents the formula gives $1.7375, charged as $1.74.
Our checked fee data holds trading fees only. It does not yet hold deposit or withdrawal fees for either venue, so this page shows none rather than a figure we have not checked.
Fee schedules change. Each figure above carries the date we read it; check the venue's own schedule before you trade.
18+ · Not financial advice · Trading involves risk of loss