Kalshi Fees: Formulas, Maker Charges and Rounding

Buying 100 Kalshi event contracts at 50 cents in a single fill costs $51.75 under the standard taker schedule: $50 for the contracts plus $1.75 in trading fees. That is a 3.5% charge relative to the purchase price—not a flat 7% commission.

As of October 10, 2026, Kalshi’s live fee schedule lists standard taker fees of $0.07–$1.75 per 100 contracts and no upcoming fee changes. Fees vary with contract price, execution type and market-specific rules. This guide covers prediction-market event contracts, not perpetual futures.

The trading-fee formula

Kalshi’s published event-contract schedule, effective July 7, 2026, gives this base taker fee in dollars, before rounding:

Taker fee = M × 0.07 × C × P × (1 − P)

• P is the execution price in dollars: 50 cents means 0.50.
• C is the number of contracts traded.
• M is the market’s taker multiplier, normally 1.

A taker order immediately matches an order already on the order book. The fee applies to that execution; it is not conditional on eventually winning. Selling before settlement is another trade and can incur another fee.

The factor P × (1 − P) is largest at 50 cents and symmetric around that price. Consequently, 10-cent and 90-cent contracts have the same base dollar fee for the same quantity and multiplier—but different fees relative to the money spent.

The fee-adjusted break-even probability

These calculations assume a single fill of 100 contracts, standard taker multiplier 1, and holding to a binary settlement paying $1 per winning contract and $0 per losing contract. They exclude funding charges and other costs.

Execution price	Contract cost	Trading fee	Total purchase cost	Break-even win probability
10¢	$10.00	$0.63	$10.63	10.63%
50¢	$50.00	$1.75	$51.75	51.75%
90¢	$90.00	$0.63	$90.63	90.63%

Fees follow Kalshi’s standard formula. Break-even probabilities are calculated as total purchase cost divided by the $100 winning payout; Kalshi describes each winning event contract as worth $1.

In the middle row, a 50% win probability produces an expected payout of $50 against a $51.75 cost. The break-even probability is therefore 51.75%, not 50%.

That does not make 51.75% the market’s “true probability.” It is a buyer’s cost-based threshold under these assumptions. Forecast interpretation and trading profitability are different measurements.

Maker orders are not always free

A maker order rests on the order book before someone else trades against it. The default maker multiplier is zero, but specified markets charge maker fees using:

Maker fee = M × 0.0175 × C × P × (1 − P)

At maker multiplier 1, the base fee is one-quarter of the standard taker fee. For 100 contracts at 50 cents, that is $0.4375 before rounding. Maker fees are charged only when the order executes; canceling an unfilled resting order carries no fee. See Kalshi’s maker-fee explanation and formula.

A limit order is not automatically a maker order. If it immediately matches available liquidity, that portion takes liquidity. A remainder may rest and later execute as maker liquidity. Kalshi’s limit-order documentation describes partial fills and warns that resting orders are not guaranteed to fill.

Check the exact series rather than assuming a category-wide rule. The live schedule lists maker fees for ATP tennis matches and US gas prices, for example, while the BTC year-end price-range series is listed with no fees. It also lists Combos excluding uncorrelated NFL with maker fees equal to 50% of taker fees—not the usual 25% relationship.

How fees are rounded

Do not assume every execution fee is rounded up to a whole cent. Kalshi’s current rounding documentation distinguishes:

• Direct members: balances aligned to $0.0001, or one-hundredth of a cent.
• Non-direct members: balances aligned to $0.01, or one cent.

The trade fee is first rounded up to six decimal places in dollars. A separate rounding adjustment aligns the balance, and the system carries rounding overpayments across fills of the same order, rebating eligible accumulated amounts.

For exact reconciliation, use the recorded net fee—trade fee plus rounding fee minus rebate—rather than multiplying a displayed, rounded single-contract fee by your quantity. Third-party futures commission merchants may also impose different charges, as the exchange schedule notes.

Deposits, withdrawals and settlement

Trading fees are separate from moving money:

• ACH deposits and withdrawals: no Kalshi fee under the published schedule.
• Card deposits: Kalshi’s deposit fee is capped at 2% in the schedule. Its card-deposit guidance says debit deposits may incur a 2% processing fee; credit-card fees can vary, and issuers may impose additional charges such as cash-advance fees.
• Debit-card withdrawals: currently listed as fee-free.
• Wire deposits: Kalshi charges no additional fee, but bank fees vary.
• Crypto transfers: third-party processor fees may apply and are disclosed before the transaction.
• Settlement and membership: no fees under the published schedule.

Keep fees separate from the forecast

For a cost calculation, start with actual execution prices and add recorded fees. If execution already reflects the spread and slippage, do not add those costs again. Our guide to prediction-market all-in cost explains that accounting and cross-venue comparisons.

For forecast research, preserve the quoted or traded probability separately from the fee-adjusted return. A market can be well calibrated—events priced near 50% happen roughly half the time—while buying those contracts indiscriminately loses money after fees. Brier score and calibration answer different questions from net profitability.

This is an explanation of market mechanics, not trading advice.