Checked against Polymarket’s documentation (11 October 2026) and Kalshi’s fee schedule (effective 7 July 2026) on 13 October 2026.
The short answer
Both use the same shape of fee: rate × contracts × price × (1 − price), paid when you trade at once. Kalshi’s general rate is 0.07 on every market. Polymarket’s is 0.07 on crypto, 0.05 on sports and most other markets, and 0.04 on politics, finance and tech. So on sports a $100 instant buy at 50¢ pays $3.50 on Kalshi and $2.50 on Polymarket; on crypto both pay $3.50. Orders that wait for their price pay nothing on Polymarket; on Kalshi they pay nothing except on a list of markets with a smaller maker fee.
To see what Polymarket fees cost you in the last 30 days, to the cent, type your Polymarket @name or paste your address into the free check above.
Side by side
| Polymarket | Kalshi | |
|---|---|---|
| Fee when you trade at once | rate × shares × price × (1 − price) | 0.07 × contracts × price × (1 − price), rounded up |
| Rate on sports | 0.05 | 0.07 |
| Rate on crypto | 0.07 | 0.07 |
| Rate on politics | 0.04 (geopolitics 0) | 0.07 |
| Order that waits for its price | No fee; gets a share of other traders’ fees | No fee, except listed markets: 0.0175 × contracts × price × (1 − price) |
| Part of the fee returned | 3% to 50% by level, since 28 May 2026 | Not in the fee schedule |
| Fee when a market settles | None | None |
| Deposits and withdrawals | No Polymarket fee (network fees may apply) | Bank transfer free; card deposits up to 2% |
Kalshi also lists some markets with a different multiplier in its schedule; check the market you trade.
A $100 instant buy, by price
| Price | Polymarket sports | Kalshi | Polymarket crypto |
|---|---|---|---|
| 20¢ | $4.00 | $5.60 | $5.60 |
| 50¢ | $2.50 | $3.50 | $3.50 |
| 80¢ | $1.00 | $1.40 | $1.40 |
On sports, Kalshi’s fee per instant trade is 40% higher at every price. On crypto the two are the same. Fees are only one part of the cost: the price you get, the spread between offers and how fast an order goes through matter too, and they differ from market to market. Any other price on Polymarket: fee calculator.
Which is cheaper for you
- Sports, buying at once: Polymarket’s rate is lower (0.05 against 0.07).
- Crypto, buying at once: the same rate on both.
- Orders that wait: free on Polymarket everywhere; on Kalshi free except the listed markets.
- Money back: Polymarket returns part of the fee to active traders and shares fees with waiting orders (what comes back).
We don’t say where to trade; that depends on the markets you want and where you can use them. These are the fees as both exchanges publish them.
Questions
Is Polymarket or Kalshi cheaper in fees?
On sports, Polymarket: its rate is 0.05 against Kalshi’s 0.07, so a $100 instant buy at 50¢ pays $2.50 against $3.50. On crypto both use 0.07. Orders that wait pay nothing on Polymarket; on Kalshi they pay a smaller fee on some listed markets.
What is Kalshi’s fee formula?
Round up of 0.07 × contracts × price × (1 − price) for orders that trade at once, and 0.0175 × contracts × price × (1 − price) for waiting orders on the markets listed in Kalshi’s fee schedule (effective 7 July 2026).
Do Polymarket and Kalshi charge a fee when a market settles?
No. Neither charges a settlement fee; the fee is paid when you trade.