Kalshi vs Polymarket fees compared: what a trade actually costs in 2026

Explainer · Updated August 8, 2026 · 18+ · Not financial advice · By BetG8 Editorial · Prediction Markets

For years the fee conversation between the two big prediction markets was simple: Kalshi charged, Polymarket didn't. That era is over. Polymarket now runs a category-based taker fee schedule, Kalshi has revised its own schedule as of July 2026, and the honest answer to "which is cheaper?" has become: it depends on what you trade, at what price, and on which side of the order book you sit. Here is the whole picture, worked through with real numbers.

Two fee models, one shape

Both venues charge takers the most at 50¢ and taper toward the extremes — a deliberate design, since a 50¢ contract carries the most uncertainty (and the most expected variance) per dollar. The difference is how they get there. Kalshi publishes a formula; Polymarket publishes per-category caps. If you mostly lift offers in liquid markets near mid-prices, you pay close to the maximums below. If you rest limit orders, you pay little or nothing on either venue.

Kalshi: the 7% formula, worked through

Kalshi's taker fee is 0.07 × price × (1 − price) per contract, rounded up to the next cent on the order total. People read "7%" and assume 7% of the stake; it is actually 7% of price × (1 − price), which peaks at a quarter of that. The July 2026 schedule revision kept the 0.07 coefficient and added a per-contract multiplier that defaults to 1 on standard markets.

Note the last column: as a share of the money you put down, Kalshi's fee is heaviest on longshots — 6.3% of stake at 10¢ versus 0.7% at 90¢. Maker fees are 0% on most Kalshi markets; on selected high-volume events the exchange applies a maker charge of roughly a quarter of the taker rate (about 0.44¢ per contract at 50¢), or a flat 0.25% on marquee events like league championships and presidential elections.

Polymarket: category caps instead of a formula

Polymarket's 2026 schedule sets a maximum taker fee per 100 shares that depends on the market category, with the fee peaking at 50¢ and declining toward the extremes, mirroring Kalshi's shape. Makers pay nothing — and a portion of taker fees funds maker rebates, so consistent limit-order traders can effectively trade at negative cost.

Notice that Polymarket's crypto cap lands exactly on Kalshi's peak fee — $1.75 per 100 at 50¢ — while every other Polymarket category undercuts it.

The same $50 order on both venues

Take the most common retail-sized trade: 100 shares at 50¢, a $50 stake, executed as a taker.

The costs that aren't on either schedule

Fee tables miss two things. First, funding rails. Kalshi takes dollars: ACH and wire transfers are free, but debit card deposits and withdrawals carry a 2% processing fee — on a $500 debit deposit that is $10, dwarfing any trading-fee difference. Polymarket charges nothing to move USDC in or out, but you pay whatever your bank or exchange charges to convert dollars to USDC and back, plus negligible Polygon network costs. Second, the spread. In a thin market, crossing a 3¢-wide book costs you more than any fee above. A venue with deeper liquidity in your market frequently beats the venue with the lower posted fee — the same lesson we drew comparing sportsbooks against prediction markets, where the vig lives in the price itself.

So which is cheaper?

On posted taker fees at mid prices: Polymarket, in every category except crypto, where they tie. On maker flow: both are effectively free, with Polymarket's rebate program a genuine edge for patient limit-order traders. On funding: Kalshi via ACH and Polymarket via an existing USDC balance are both free; Kalshi via debit card is the expensive path. What the schedules cannot tell you is where your specific market is deepest — and note that access differs by state and by category: several US states currently restrict Kalshi's sports contracts entirely, a moving map we track in our state-by-state legality series. For how these venues price events in the first place, start with how election prediction markets work. This is analysis, not a recommendation to trade anywhere.

FAQ

Which has lower trading fees, Kalshi or Polymarket?

At 50¢, Polymarket takers pay up to $1.00–$1.25 per 100 shares in most categories versus $1.75 on Kalshi; crypto is $1.75 on both; Polymarket geopolitics is free. Makers pay little or nothing on either.

Does Polymarket still charge no fees?

No — since 2026 it charges category-based taker fees capped between $1.00 and $1.75 per 100 shares, with geopolitics exempt. Deposits, withdrawals and maker orders remain free.

How is Kalshi's fee calculated?

0.07 × price × (1 − price) per contract, rounded up to the next cent — peaking at 1.75¢ per contract at 50¢. Maker fees are 0% on most markets.

Are there deposit or withdrawal fees?

Kalshi: ACH/wire free, debit card 2%. Polymarket: free, aside from what your bank or exchange charges to convert to and from USDC.

Sources

• Kalshi fee schedule
• OddsShopper: Kalshi fees
• pm.wiki: Kalshi fee schedule 2026
• Start Polymarket: 2026 fee table
• Prediction Hunt: Polymarket fees guide
• KuCoin: Polymarket fees 2026

Next: sportsbook vs prediction market — where is the better price?

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