- There is no single best prediction market. The right one depends on what you trade, where you live and whether you place resting orders or take the price on screen.
- Both Kalshi and Polymarket publish a fee formula that peaks at 50¢ and shrinks toward 0¢ and $1. On 100 contracts at 50¢, Kalshi's standard taker fee is $1.75 and the Polymarket taker fee ranges from $0 to $1.75 depending on category.
- Resting orders are the cheaper route on both: Kalshi's default maker multiplier is 0 and Polymarket's maker fee is 0, as of the Kalshi schedule effective 2026-07-07.
- Fees are only one input. Rules, which markets exist and whether you can use the platform at all matter more for most readers.
There is no single best prediction market. Kalshi and Polymarket, two of the best-known venues, are built differently, and which is cheaper depends on the trade. This article compares them on the one thing we can verify exactly: the published fee formulas. Fee figures come from each platform's own documentation, listed in the sources. The worked examples are our arithmetic on those formulas, not quotes from the platforms, and nothing here is advice. For how we handle data, see our methodology.
What makes a prediction market "best"
A prediction market is an exchange where you buy contracts that pay $1 if an event happens and nothing if it does not, so the price in cents reads as an implied probability. If that is new, start with what prediction markets are and how to read a price as a probability.
Four things decide which platform suits you:
- Access. Which platforms you may use depends on your location and each platform's terms. Check the platform's own rules before depositing anything.
- Market selection. Sports, politics, economics and crypto markets are not offered equally everywhere. Browse the live markets hub to see what is open today.
- Fees. Covered below.
- Rules and settlement. Each market has written resolution rules. Reading them before you trade matters more than a cent of fees.
How the Kalshi and Polymarket fee formulas work
Both platforms charge takers (orders that match an existing offer immediately) a fee that depends on the price. Both use the same shape: a rate times the price times one minus the price, per contract. That product is largest at 50¢ and falls toward zero as the price approaches 0¢ or $1.
Kalshi. Its fee schedule gives the taker fee as rounded-up (multiplier × 0.07 × contracts × price × (1 − price)), with a standard multiplier of 1. Maker fees use a 0.0175 rate, but the default maker multiplier is 0, so makers on standard markets pay nothing. Combination markets carry a taker multiplier of 2. The schedule we used is effective 2026-07-07, and the schedule's own worked figures are $1.75 for 100 contracts at 50¢ and $0.63 for 100 contracts at 90¢.
Polymarket. The fee documentation (see sources) gives the taker fee as contracts × rate × price × (1 − price), where the rate depends on the category, and makers pay nothing. Crypto is 0.07. Sports, economics, culture, weather and other markets are 0.05. Politics, finance, tech and mentions are 0.04. Geopolitics is 0.
Fee comparison on 100 contracts
The table applies those formulas to a 100-contract taker order, before rounding (Polymarket rounds fees to 5 decimal places). Kalshi figures are the standard-market taker fee. Prices are hypothetical, and the formulas are those published in the sources at the 2026-10-07 snapshot.
| Platform and category | Rate | At 50¢ | At 90¢ |
|---|---|---|---|
| Kalshi, standard market | 0.07 | $1.75 | $0.63 |
| Polymarket, crypto | 0.07 | $1.75 | $0.63 |
| Polymarket, sports | 0.05 | $1.25 | $0.45 |
| Polymarket, politics | 0.04 | $1.00 | $0.36 |
| Polymarket, geopolitics | 0 | $0.00 | $0.00 |
Read it this way. For a standard Kalshi market and a Polymarket crypto market the taker fee is identical at the same price. Polymarket's non-crypto categories are cheaper, and geopolitics is free for takers. Kalshi's rounding up matters mostly on tiny orders: one contract at 50¢ comes to $0.02.
Run your own numbers in the fee calculator rather than relying on this table for a specific trade.
Where the fee gap does not matter
On a 100-contract trade at 50¢ the largest gap in the table is $1.75. That is small next to the spread, the gap between the best buy and sell price. A thin market with a spread of several cents costs more than the fee. So the practical test is liquidity: look at the order book on the exact market you want before comparing fee schedules.
The fee shape also has a lesson for pricing. Because the charge falls toward the ends of the price range, a contract at 90¢ costs a taker far less in fees than one at 50¢. But the fee is small in cents, not small relative to the payoff: at 90¢ it is a larger share of the 10¢ you stand to win than it is of the 50¢ at stake on a 50¢ contract. Judge any trade on net payoff after fees, not on the headline price.
Other platforms worth a look
Kalshi and Polymarket are not the only venues. Our Gemini Predictions review covers another exchange that lists event contracts with its own market data and fee terms, and our platform comparison keeps the current side-by-side of what each one offers. We do not compare Gemini's fees here, because they are not in the fact pack this article is built on.
For head-to-head detail on the two biggest names, see Kalshi vs Polymarket, and the individual reviews: Kalshi and Polymarket.
Where this can go wrong
- Fee schedules change. The Kalshi schedule we used is effective 2026-07-07. Check the current version before you rely on a figure.
- Rounding. Kalshi rounds fees up. Polymarket rounds to 5 decimal places, so our unrounded figures are within a fraction of a cent of a real fill.
- Fees are not the whole cost. Spreads, slippage, deposit and withdrawal costs, and the time your money is tied up are not in the table.
- Categories can be reclassified. A market's category sets its Polymarket rate, so confirm the rate on the market you are trading.
- Different products. A free category on one platform does not mean the same market exists on the other.
Frequently asked questions
What is the best prediction market?
It depends on what you trade and where you live. On fees alone, Polymarket's non-crypto categories are cheaper than Kalshi's standard taker fee at the same price, while its crypto category matches Kalshi. Access, market selection and liquidity usually decide the question first.
What are the two major prediction markets?
The two we compare most often are Kalshi and Polymarket. Both appear in the table above. Other exchanges, such as Gemini, list event contracts too, and our platform comparison page tracks them.
Do people make money on prediction markets?
Some do, but fees and spreads are a cost on every trade. For what a tracked group of profitable wallets looks like, read who actually makes money on Polymarket.
Are prediction markets a good investment?
A contract pays $1 or nothing, so it is closer to a bet on a single outcome than a long-term holding. Size positions as money you can afford to lose, and compare the net payoff after fees.
The short version
Pick the venue where you can legally trade, where the market you want is liquid, and where the rules are clear to you. Then use the fee formulas to compare the actual trade: resting orders are free on both platforms we checked (Polymarket's documentation also lists maker rebates, which we have not quantified), and taker costs peak near 50¢. You can browse today's open contracts on the politics and sports pages.