Kalshi does not charge a flat percentage on trades. That single fact confuses more new traders than anything else on the platform, because most people arrive expecting a simple "2% fee" line item like a brokerage commission. Instead, Kalshi fees are calculated with a formula tied to contract price, which means the same trade can cost you $0.63 or $1.75 depending entirely on where the market is pricing the outcome. Understanding kalshi fees is the difference between a strategy that's actually profitable and one that looks profitable until the fee line eats the edge.
This guide breaks down exactly how much does Kalshi charge, how the fee formula works with real numbers, what withdrawals and deposits cost, and how the whole kalshi fee structure stacks up against Polymarket. Kalshi processed roughly $9.8 billion in monthly volume as of February 2026 and generated approximately $260 million in 2025 revenue — almost entirely from trading fees. That revenue has to come from somewhere, and it comes from a formula most traders never bother to read.
We'll also cover the parts Kalshi's help center glosses over: instant withdrawal costs, debit card deposit fees, and why "maker/taker fees" doesn't mean the same thing on Kalshi that it means on Polymarket. If you're deciding between the two platforms, see our full Polymarket vs Kalshi comparison for the complete picture beyond fees alone.
Kalshi Fee Structure at a Glance
| Fee Type | Amount | When It Applies |
|---|---|---|
| Trading fee | Formula-based, ~1-4% of notional | Every filled trade (buy and sell) |
| Maker rebate | None (uniform fee) | N/A — Kalshi doesn't discount resting orders |
| Settlement/resolution fee | $0 on most markets | Some markets charge a small settlement fee |
| ACH deposit | Free | Standard bank transfer, 1-3 business days |
| Debit card deposit | ~1.5-3% | Instant funding |
| ACH withdrawal | Free | 1-3 business days |
| Instant withdrawal | ~1.5% fee | Same-day payout to debit card |
| Idle cash yield | ~4% APY | Uninvested balance sitting in your account |
That idle cash yield is one of Kalshi's real structural advantages. Polymarket pays 0% interest on balances sitting in USDC, while Kalshs's ~4% APY means your uncommitted cash is earning something even when you're not actively trading.
How Kalshi Calculates Its Trading Fee
Kalshi's trading fee isn't a flat percentage — it's calculated using a formula that scales with how close the contract price sits to 50 cents. The general formula is: fee = round up (0.07 × contracts × price × (1 − price)), where price is expressed in dollars between $0.01 and $0.99. This formula applies on both sides of a trade — buying and selling both trigger a fee calculation, so a full round-trip trade pays the formula twice.
Here's what that means in practice. A contract trading at exactly $0.50 sits at the peak of the fee curve, because 0.50 × 0.50 = 0.25 is the maximum value that price × (1-price) can produce. That means coin-flip markets carry the highest dollar-for-dollar fee rate on the platform. A contract trading at $0.10 or $0.90 sits near the bottom of the curve in dollar terms, but the fee still represents a larger percentage of your actual stake because your notional exposure is smaller.
This is the opposite of how most traders assume fees work. You'd expect long-shot bets to be cheaper across the board, but Kalshi's formula actually charges a higher fee rate relative to your stake on lopsided markets than it does on 50/50 coin flips, even though the dollar amount is smaller. If you're running strategies across both Polymarket and Kalshi, this formula difference matters — see our guide on prediction market strategies and how to profit for how fee structure should shape which platform you route a given trade through.
Kalshi Maker vs Taker Fees
Here's where Kalshi's fee structure diverges sharply from Polymarket's. Polymarket charges taker fees of 0.75% to 1.80% depending on category (expanded March 30, 2026) while makers trade free and earn 20-50% rebates for providing liquidity. Kalshi does not run this two-tier system. The same formula-based fee applies whether you're the maker resting a limit order in the book or the taker crossing the spread to fill immediately.
Some Kalshi markets do waive fees entirely for specific promotional periods or specific contract types, and Kalshi has experimented with zero-fee maker incentives on select high-volume markets to build liquidity. But there's no permanent structural discount for providing liquidity the way Polymarket built into its taker/maker model. If your strategy depends heavily on capturing maker rebates, Polymarket's fee structure rewards that behavior in a way Kalshi's currently doesn't. Our Polymarket fees explained guide breaks down exactly how those rebates stack up.
Kalshi Contract Fees Across Market Categories
Kalshi applies its fee formula uniformly across most market categories — politics, economics, weather, and the fast-growing sports vertical all use the same 0.07 multiplier in the base case. This is different from Polymarket, which set category-specific taker fee tiers ranging from 0.75% to 1.80% after its March 2026 expansion. Kalshi's simplicity cuts both ways: it's easier to predict your fee cost across different bet types, but it means Kalshi doesn't offer the same cheaper-fee incentive Polymarket does for lower-volatility categories.
Sports markets deserve a specific mention because they now represent more than 80% of total prediction market volume industry-wide. Kalshi's sports offering has grown fast enough to compete directly with Polymarket and DraftKings-style books, and the fee formula applies the same way to a Super Bowl winner contract as it does to a Fed rate decision market. If you're comparing where to place sports-specific trades, our breakdown of the best prediction markets for sports betting covers fee-adjusted returns across platforms, and our prediction markets vs sports betting piece explains how this fee model compares to a traditional sportsbook's vig.
Kalshi Deposit and Withdrawal Fees
Funding a Kalshi account through standard ACH bank transfer costs nothing and typically clears within one to three business days. Debit card deposits process instantly but carry a fee, generally in the 1.5% to 3% range depending on your card issuer's cash-advance-style processing. Wire transfers are available for larger deposits but come with your bank's own wire fee on top of anything Kalshi charges.
Withdrawals follow the same split. Standard ACH withdrawal back to your linked bank account is free and takes one to three business days to settle. Instant withdrawals to a debit card process the same day but carry a fee around 1.5% of the withdrawal amount. This mirrors the tradeoff Polymarket traders face with USDC withdrawals — see our guide on how to withdraw from Polymarket for the crypto-side equivalent, including gas costs on Polygon that Kalshi's USD settlement avoids entirely.
The practical takeaway: if you're not in a rush, every dollar you move on or off Kalshi through standard ACH costs you nothing beyond the trading fee itself. The instant options exist for convenience, and convenience has a price.
What Kalshi Pays You on Idle Cash
Kalshi pays approximately 4% APY on uninvested cash sitting in your account. This isn't a marketing gimmick — it's a real structural difference from Polymarket, which settles in USDC on Polygon and pays 0% interest on balances. If you keep $10,000 parked in a Kalshi account for a year while actively trading only a portion of it, that idle cash generates roughly $400 in interest that Polymarket simply doesn't offer.
This matters more than it sounds for anyone running a portfolio across multiple markets rather than deploying 100% of capital at once. Traders who hold cash reserves for opportunistic entries, or who size positions conservatively, effectively get paid to wait on Kalshi. It's a meaningful factor when weighing kalshi vs polymarket fees holistically rather than just comparing per-trade costs.
Kalshi Fees vs Polymarket Fees
| Category | Kalshi | Polymarket |
|---|---|---|
| Trading fee model | Formula-based (~0.07 × C × P × (1-P)) | 0.75%-1.80% taker fee by category |
| Maker incentive | None structural | Free trades + 20-50% rebates |
| Settlement currency | USD | USDC on Polygon |
| Idle balance yield | ~4% APY | 0% |
| Regulatory status | CFTC-regulated DCM | Acquired QCEX for $112M for CFTC license |
| Deposit method | ACH (free), debit (fee) | USDC transfer, on/off-ramp fees |
| Withdrawal speed | 1-3 days (ACH) or instant (fee) | On-chain, gas-dependent |
| Tax reporting | Issues 1099-MISC | Issues nothing globally |
Kalshi wins on idle cash yield and on predictable USD settlement with no gas fees. Polymarket wins on maker rebates for liquidity providers and on its lower published taker fee ceiling for high-volume categories. Neither platform is simply "cheaper" across the board — the answer depends on your trade size, how close to 50 cents your typical entry price sits, and whether you're providing or taking liquidity. Our full Polymarket vs Kalshi guide walks through the non-fee factors — market selection, mobile experience, and regulatory footprint — that should also factor into your choice.
Real Trade Math: Three Examples
A $50 position on a contract priced at $0.50 (100 contracts) generates a fee of roughly $1.75 using Kalshi's formula — about 3.5% of your stake. That's a meaningful drag if you're trading frequently at coin-flip prices, and it's higher than Polymarket's 0.75% floor tier for the same trade size.
A $10 position on a long-shot contract priced at $0.10 (100 contracts) generates a fee of roughly $0.63 in dollar terms, but that's 6.3% of your $10 stake — a worse percentage cost despite the smaller dollar figure. This is the counterintuitive part of Kalshi's fee curve: extreme-probability markets don't automatically mean cheaper trading relative to your stake.
A $500 position on a contract priced at $0.80 (625 contracts) generates a fee of roughly $8.75, or about 1.75% of notional. As your trade size grows and your entry price sits toward the extremes, the percentage cost relative to stake improves. Larger, more lopsided trades are where Kalshi's fee structure actually becomes competitive with — or cheaper than — Polymarket's flat percentage model.
The Catch: Hidden Costs Beyond the Published Fee Schedule
Every fee schedule has a catch, and Kalshi's is the formula's non-obvious behavior at extreme prices. Traders who assume long-shot bets are automatically cheap because the dollar fee looks small often miss that the percentage cost relative to stake is actually higher there than at 50/50. That's a real trap for anyone building a strategy around cheap long-shot accumulation.
Instant withdrawal fees are another quiet cost. If you're moving money in and out of Kalshi frequently rather than letting cash settle over a few days, the 1.5% instant withdrawal fee compounds fast — ten instant withdrawals a month at $1,000 each is $150 in fees you didn't have to pay. And because Kalshi is a CFTC-regulated designated contract market, it issues a 1099-MISC for your winnings, meaning your tax reporting is handled for you in a way Polymarket's silence on tax forms isn't. See our guide on how prediction market winnings are taxed for what that 1099-MISC actually means at filing time, especially with the OBBBA 90% gambling loss cap taking effect for tax year 2026.
The Honest Reality Check
The IRS has issued zero formal guidance on how prediction market winnings should be classified for tax purposes, which means the 1099-MISC Kalshi sends you doesn't settle the underlying tax question — it just reports the number. Whether your Kalshi winnings should be treated as ordinary income, gambling income, or under Section 1256 is a live debate among tax professionals, not a solved problem. Don't assume the form Kalshi sends you is the final word on how to report it.
Fee formulas also punish frequent, small, coin-flip trading more than they punish patient, larger, lopsided-price trading. If your strategy is scalping 50/50 markets with small size, Kalshi's fee curve is working against you harder than it looks on paper. Regulatory status matters here too — Kalshi operates as a CFTC-regulated DCM available in 40+ states, while ongoing state-level fights (Arizona's criminal charges against Kalshi in March 2026, adverse rulings in Nevada, Massachusetts, Maryland, and Ohio) mean your access and the platform's fee structure could shift depending on where you live. Check our state-by-state legal map and our broader guide to whether prediction markets are legal in the US before assuming your state's access is guaranteed long-term.
Where to Go From Here
If you're still deciding between platforms, start with our full Kalshi review and Polymarket review for the non-fee factors, or the ranked best prediction market apps guide for how both stack up against Robinhood's Kalshi-powered prediction hub and other emerging platforms. For the mechanics behind how these markets price contracts in the first place, our how prediction markets work pillar page covers the fundamentals this fee formula builds on.
Frequently Asked Questions
How much does Kalshi charge in trading fees?
Kalshi uses a formula-based fee: roughly 0.07 × contracts × price × (1 − price), rounded up to the nearest cent. On a $0.50 contract, that's about 3.5% of your stake; the percentage shifts at other prices. See the Polymarket vs Kalshi comparison for how that stacks up against Polymarket's flat 0.75%-1.80% taker fee.
Is Kalshi free to trade?
No. Kalshi charges a trading fee on every filled order using its price-based formula, though some promotional markets have waived fees temporarily. There's no free trading tier the way Polymarket offers free maker orders with rebates.
Does Kalshi have maker and taker fees like Polymarket?
Not structurally. Kalshi applies the same formula-based fee to makers and takers, unlike Polymarket, which charges takers 0.75%-1.80% while makers trade free and earn rebates. See our Polymarket fees explained guide for the maker/taker breakdown on that side.
What are Kalshi's withdrawal fees?
Standard ACH withdrawals to your bank account are free and take one to three business days. Instant withdrawals to a debit card carry a fee, typically around 1.5% of the amount withdrawn.
Does Kalshi charge fees on deposits?
ACH bank transfers are free to deposit. Debit card deposits process instantly but carry a fee, generally 1.5% to 3% depending on your card issuer.
Does Kalshi pay interest on my account balance?
Yes. Kalshi pays approximately 4% APY on uninvested cash sitting in your account, a real advantage over Polymarket, which pays 0% interest on USDC balances.
Are Kalshi's fees higher than Polymarket's?
It depends on trade size and price. At 50/50 prices, Kalshi's formula-based fee can exceed Polymarket's flat rate; at extreme prices with larger position sizes, Kalshi often comes out cheaper. Run the math on your specific trade before assuming either platform is universally cheaper.
Does Kalshi report my winnings to the IRS?
Yes. Kalshi issues a 1099-MISC for winnings, unlike Polymarket, which issues no tax forms globally. That doesn't resolve how you should classify the income for tax purposes — see our prediction market tax guide for the three possible treatments the IRS hasn't formally ruled on.
