Kalshi fees explained (plus Polymarket fees and Kalshi taxes)

Kalshi’s main fee is a trading fee of 0.07 × contracts × price × (1 − price), rounded up, charged only when your order takes an existing price. That’s $1.75 on 100 contracts at 50¢ and $0.63 at 10¢ or 90¢. Bank deposits and all standard withdrawals are free. Below we break down every Kalshi fee as of October 2026, compare Polymarket’s fees, and explain what’s known about Kalshi taxes.

Kalshi trading fees

Kalshi’s fee schedule (effective February 5, 2026) sets two formulas, where C is the number of contracts and P the price in dollars:

• Taker fee: “round up(0.07 x C x P x (1-P))”. This applies when your order matches immediately with an order already on the book.
• Maker fee: “round up(0.0175 x C x P x (1-P))”. This applies only on markets Kalshi lists as having maker fees, and only when a resting order fills. Cancelling costs nothing.
• No settlement fee and no membership fee.

The P × (1 − P) term means fees peak at 50¢ and fall toward the extremes. Kalshi’s help centre describes this as a fee “on the expected earnings on the contract.”

Which Kalshi markets charge maker fees?

Most don’t. We pulled every series from Kalshi’s public API on October 17, 2026. About 160 of more than 15,000 series carry maker fees, mostly major sports games (the NFL, NBA and NHL game series, for example) plus some economics markets such as the Fed rate series. A handful are fee-free, and since August 2026 some MLB series have run at a 0.5 fee multiplier. The app shows the fee before you confirm a trade, so check there for any specific market.

Rounding

The PDF schedule says fees round up “to the next cent.” Kalshi’s newer API documentation adds that fees accumulate across all fills of one order, “so that the total fee converges to what a single equivalent fill would cost.” In practice, splitting one order into many small fills shouldn’t cost you more.

Combos (parlays)

Combos are priced through a request-for-quote system. Under a fee update Kalshi filed with the CFTC on July 12, 2026, a trader accepting a quote pays the equivalent of a taker fee, and the quoter pays the equivalent of a maker fee.

Our Kalshi fee framework: fee as a share of your stake

The per-contract fee is largest at 50¢, but what really matters is the fee as a share of what you put up. Divide the taker fee by the price and you get a simple rule: Kalshi’s taker fee costs 7% × (1 − price) of your stake. Cheap long shots therefore cost the most per dollar:

The takeaway: if you like buying contracts under 25¢, fees eat 5–6% of every stake as a taker. Posting a limit order instead (free on most markets, 0.0175 where maker fees apply) is the single biggest fee saving available.

Kalshi deposit and withdrawal fees

All figures are from Kalshi’s help centre as of October 2026. To avoid every Kalshi deposit fee, fund by bank transfer.

Polymarket fees

Polymarket runs two products with different fees.

• Polymarket US (the CFTC-regulated app for US users): takers pay 0.0695 × contracts × price × (1 − price), rounded to the nearest cent, so $1.74 on 100 contracts at 50¢. Makers aren’t charged. From 1:00 p.m. ET on October 19, 2026, maker and taker rebates move to monthly volume tiers: makers need $10 million or more of monthly volume to earn a rebate, and takers $250,000. Unfilled orders cost nothing. Withdrawals are free (“Withdraw your cash balance securely and for free”). Polymarket US’s docs don’t list a deposit fee.
• Polymarket international (polymarket.com, not open to US residents): a per-category taker rate, 0.07 for crypto, 0.05 for sports, and 0.04 for politics, finance and tech. Geopolitical and world-events markets are fee-free, and “makers are never charged fees.” There are no Polymarket fees to deposit or withdraw USDC.

For a fuller platform comparison, see Kalshi vs Polymarket.

Kalshi taxes: what we know

General information only, not tax advice. Tax treatment of prediction markets is unsettled, so speak to a tax professional.

What Kalshi sends you. Kalshi’s help centre says users who pass IRS reporting thresholds receive a 1099-MISC for credits and rewards, a 1099-INT for interest, a 1099-B for crypto transfers and a 1099-DA from its crypto partner ZeroHash. It doesn’t issue a 1099 for profits from trading event contracts. Instead, you can download a profit and loss statement under Account → Tax Info. The statement uses first-in, first-out accounting, includes fees and rebates, and is updated on the first of each month.

One threshold to know. Kalshi’s SSN article still cites “more than $600 in incentive credits” as a reporting trigger. The IRS says the One Big Beautiful Bill Act raised that information-return threshold to $2,000 for payments made after December 31, 2025.

How winnings may be taxed. We found no IRS ruling, notice or FAQ on event contracts. That leaves three possible treatments, and tax advisers disagree on which applies:

1. Gambling income (IRS Topic 419). Losses are deductible only if you itemise, and only up to your winnings. The IRS confirms that from tax year 2026 the deduction for wagering losses is capped at 90% of losses. Whether that cap applies to event contracts isn’t established.
2. Section 1256 contracts: regulated futures traded on a CFTC-designated contract market get 60% long-term / 40% short-term capital-gains treatment. Kalshi is a designated contract market, but the IRS hasn’t said whether event contracts qualify.
3. Ordinary capital gains or other income. The Congressional Research Service noted in August 2026 that event contracts are “currently in the aggregate taxed at a lower rate” than state-regulated sports betting.

Whatever the treatment, keep your Kalshi P&L statement and any 1099s. Before filing, check our Kalshi review for current account details, and whether Kalshi is legal in your state.

18+ (21+ where required). Prediction markets involve risk of loss — only trade what you can afford to lose. Gambling problem? Call or text 1-800-MY-RESET (National Problem Gambling Helpline, 24/7).

Last updated 2026-10-17. Not financial or betting advice.