Kalshi vs Polymarket Fees: Full 2026 Cost Breakdown

Kalshi (opens in a new tab) and Polymarket (opens in a new tab) are the two largest prediction markets accessible to California traders. They look similar from the outside, but their fee structures, deposit methods, and effective costs are genuinely different. Here's a side-by-side breakdown for anyone deciding where to put their first $500, or their next $50,000.

What does Kalshi charge?

Kalshi charges a per-contract trading fee scaling with contract price that averages approximately $0.07 per round-trip trade, while offering free ACH deposits and withdrawals.

Kalshi uses a per-contract trading fee that scales with contract price. The standard fee is roughly $0.07 per contract for round-trip trades on most markets, with reduced fees on lower-priced contracts and high-volume markets. Kalshi does not charge deposit or withdrawal fees for ACH bank transfers.

Wire transfers and debit card deposits incur small processing fees. Withdrawals via ACH are free and typically settle in 1-3 business days.

There is no monthly minimum, no inactivity fee, and no spread markup beyond the natural bid-ask of the order book.

What does Polymarket charge?

Polymarket US shows its trading fee on each order before you confirm, and its app trades in US dollars.

Polymarket US shows a trading fee on each order in its app before you confirm. Because the app trades in US dollars, there is no crypto settlement layer to pay for.

The real cost picture is the same on both platforms. Three things add up:

• Trading fee: shown on each order. Kalshi's is per contract; the Polymarket US app lists its own.
• Bid-ask spread: the gap between buy and sell prices, wider on thin markets.
• Withdrawals: Kalshi's ACH withdrawals are free. Polymarket US: free. The money goes back to the method you deposited with, once the deposit has cleared (usually 3 to 4 business days). Wire withdrawals go through support.

For most retail traders depositing under $5,000, the all-in cost ends up roughly comparable to Kalshi.

Compare the fee on each order and the spread, not just the headline.

Which has lower spreads?

On the highest-volume markets, major elections, championship games, Fed decisions, both platforms run 1-2 cent spreads. The difference is invisible at retail size.

On thinner markets, Polymarket often has tighter spreads on crypto-native and political contracts (its core user base). Kalshi often has tighter spreads on regulated US sports, weather, and macro markets where it has institutional liquidity providers.

How do deposits compare?

Kalshi accepts: ACH bank transfer (free, 1-3 days), wire (small fee, same-day), debit card (1.5%, instant).

Polymarket accepts: US-dollar deposits inside the Polymarket US app. No crypto wallet is needed.

Both are straightforward to fund.

What about withdrawals?

Kalshi: ACH withdrawals are free and settle in 1-3 business days. There are no withdrawal limits for verified accounts up to standard daily caps.

Polymarket: withdrawals are free and go back to the method you deposited with, once the deposit has cleared (usually 3 to 4 business days). For full guides see how to deposit on Polymarket and how to withdraw from Kalshi.

Which is more tax-friendly?

Kalshi provides a profit-and-loss statement for your trades; for Polymarket US, check the tax documents its app provides. The IRS hasn't said how event contracts are classified, so neither is more tax-friendly yet.

Kalshi, for now. Kalshi provides a profit-and-loss statement for your trades. Section 1256 60/40 treatment is argued by some, but the IRS hasn't said how event contracts are classified. Polymarket US is also a regulated exchange; check its app for the tax documents it provides, and keep your trade history either way. For the full picture, see our tax guide.

What's the all-in cost on a typical trade?

Hypothetical: you buy 100 contracts at $0.50, sell at $0.65, on the 2026 California governor market.

• Kalshi: profit = $15. Trading fees roughly $1.40 round trip. Net ≈ $13.60.
• Polymarket US: profit = $15, minus the trading fee the app shows on each order. There are no crypto deposit or withdrawal costs.

The pattern: on a trade this size, the difference comes down to each platform's fee on the order and the spread. Kalshi wins on device choice and tax reporting; Polymarket often wins on market depth.

Which should I use?

Beginners should choose Kalshi for its regulatory oversight and simplicity, while active traders often prefer Polymarket for its deep liquidity and extensive political markets.

If you're new, start with Kalshi. It's simpler, US-regulated, works on every device, and the tax picture is cleaner. If you're an active trader who wants the deepest political markets, add Polymarket. Most serious traders end up using both.

For a deeper feature comparison, see Kalshi vs Polymarket. For the legal context, see prediction markets in California.

Sources

• Kalshi: fees (opens in a new tab)
• Polymarket: Learn: fees and trading (opens in a new tab)
• CFTC, DCM-registered exchanges (opens in a new tab)

About the author

Catie Di Stefano

Catie Di Stefano has spent 15 years in the regulated gambling industry, starting at Betsson Group in Malta and spending nearly five years at Gaming Innovation Group (GiG) before building an independent consultancy across European and US iGaming brands, including a licensed engagement with Hard Rock Hotel & Casino Atlantic City under a New Jersey DGE vendor license. She's been interviewed by the California Business Journal on the rise of online gambling in the US, and spoke on a 2022 Next.io panel specifically about California's gaming market. She went on to build the OnlineGamblers.com brand and hold marketing director roles at Smartico.ai and Vegas Kings, and has been named to multiple iGamingExpress industry rankings. She now covers regulated prediction markets full-time.

Editorial standards: How we research and rank

Which is cheaper, Kalshi or Polymarket?

It depends on the market and your order size. Kalshi charges a per-contract fee and has free ACH transfers. The Polymarket US app shows its fee on each order and has no crypto conversion costs. Compare the total cost, including the bid-ask spread, on both before you trade.

What does Kalshi charge per trade?

Kalshi charges roughly $0.07 per contract round trip on most markets, with reduced fees on lower-priced contracts and high-volume markets.

Does Polymarket charge any fees?

Yes. Since October 2026, Polymarket US charges a price-based taker fee (highest near 50¢, about $1.74 per 100 contracts). Orders that rest on the book pay no fee; rebates on them are limited to very high-volume traders since October 19, 2026. The app shows the fee on each order before you confirm. Because it trades in US dollars, there are no crypto network or conversion fees. Check the app's fee schedule for current rates.

Are deposits free on Kalshi?

ACH bank transfers are free. Wire transfers and debit card deposits incur small processing fees.

Is Kalshi cheaper than Polymarket?

It depends on the contract. Kalshi's per-contract fee is lowest on very cheap and very expensive contracts and highest near 50¢. The Polymarket US app shows its fee on each order. For a typical NFL or NBA order, compare both fees and the spread before you place it.

Does Polymarket charge deposit or withdrawal fees?

No. Polymarket US withdrawals are free. Since October 2026 it charges a taker fee on trades that fill straight away (highest near 50 cents, about $1.74 per 100 contracts). Orders that rest on the book pay no fee; rebates on them are limited to very high-volume traders since October 19, 2026. Card, bank, Apple Pay, PayPal and Venmo deposits carry no listed fee. Kalshi is fee-free on ACH deposits and withdrawals for California residents.

Do you pay taxes on Kalshi and Polymarket winnings in California?

Yes. Net profits from either platform are taxable federally (the IRS hasn't said how event contracts are classified), and California residents also owe state income tax. Kalshi provides a profit-and-loss statement for your trades; for Polymarket US, use the app's trade history and any tax documents it provides to calculate your gain.

Which has better spreads?

On highest-volume markets, both platforms run 1-2 cent spreads. Polymarket often has tighter spreads on crypto-native and political contracts; Kalshi often has tighter spreads on US sports and macro markets.

Does Crypto.com charge trading fees for its California event markets?

Crypto.com, ranked as the number two platform for Californians, utilizes a fee structure that is distinct from Kalshi. Polymarket US charges a price-based taker fee since October 2026; Crypto.com may include costs within the bid-ask spread or via small transaction fees per contract. Traders should check the current contract specifications in the mobile app before execution.

What are the hidden costs of using Polymarket?

The Polymarket US app trades in US dollars, so there are no crypto conversion or network fees. The costs to watch are the trading fee shown on each order and the bid-ask spread, which can be wide on thin markets.