Kalshi fees, explained: what you pay, when, and what actually costs you more

By Ken So, Octagon Research Editor

Kalshi charges one main fee: a per-contract trading fee at execution, scaled to the contract's price — peaking for contracts near 50¢ and shrinking toward zero at the extremes. Settlement is free, and there are no maintenance fees. For most traders, though, the bigger real cost isn't the fee at all — it's the bid-ask spread on thinner markets, which can be several times larger.

The fee model in one idea

Kalshi's trading fee scales with price × (1 − price) — a curve that peaks at 50¢ and falls to almost nothing near 1¢ or 99¢. Two consequences follow:

• Coin-flip contracts cost the most to trade. The fee is at its maximum exactly where uncertainty is highest.
• Near-certain contracts are cheap. Buying a 95¢ contract to collect the last nickel isn't destroyed by fees — but the spread still might, see below.

The precise current rates, and any maker/taker or member-tier distinctions, live on Kalshi's published fee schedule — they've been revised before, so check the source rather than a screenshot from last year. What's stable is the shape: price-scaled at execution, free at settlement.

The cost nobody itemizes: the spread

On deep markets — Fed decisions, headline elections — the book is tight and the fee is your main cost. On the long tail of smaller contracts, the bid-ask gap is routinely several cents. Cross a 6-cent spread with a market order and you've paid a "fee" many times larger than Kalshi's, invisibly. Two habits protect you:

• Use limit orders on thin markets — join the book instead of crossing it, and let someone cross to you.
• Check depth before sizing. A 500-contract position in a book showing 40 contracts at the touch will move the price against you as it fills.

A worked example

Say you buy 100 YES at 44¢ on a market you believe is 55% likely. Your gross expected value is 11¢ per contract — $11.00 on the position. Now subtract the round trip: a price-scaled fee at entry (largest in exactly this mid-price zone), a fee again at exit if you sell before settlement, and — when your exit crosses the book rather than resting as a maker order — the spread on top. Fees and spread are additive costs, not alternatives. If those total 3¢ per contract, your realistic edge is nearer $8 — still a good trade. If your believed edge were only 3¢, the same costs would erase it entirely. Fees don't change whether your probability estimate is right; they raise the bar for how right it has to be. The full framework is in calculating expected value, and how platform rules shape prices generally in how fees and platform rules affect prediction market prices.

Kalshi vs Polymarket on cost

Polymarket historically charges no taker fee — its cost lives entirely in the spread of its AMM-orderbook hybrid. Kalshi charges explicit per-contract fees with generally tighter regulated-market spreads on US-focused contracts. Which is cheaper depends on the specific contract's depth, not the fee table; the structural comparison is in Polymarket vs Kalshi.

Frequently asked questions

What fees does Kalshi charge?

Kalshi charges a per-contract trading fee when an order executes, scaled to the contract price — largest for contracts near 50 cents, shrinking toward zero at the price extremes. Settlement itself is free: if you hold to resolution, winners receive the full $1.00 per contract with no exit fee. Exact current rates and any maker/taker distinctions are published on Kalshi's own fee schedule.

Why do Kalshi fees depend on the contract price?

The fee formula scales with price × (1 − price), which peaks at 50 cents. The intuition: a 50-cent contract carries the most uncertainty, and fee-scaling by that measure keeps costs proportionally small on near-certain contracts, so late-stage 95-cent trades aren't eaten by fees.

Is the spread a fee?

Not formally, but it's often your largest cost. On thin markets the gap between best bid and best ask can be several cents; crossing it with a market order costs you that gap immediately. On small contracts, the spread routinely exceeds the trading fee — check the book before sizing.

Does Kalshi charge deposit or withdrawal fees?

Standard bank-transfer funding and withdrawals have historically been free or near-free, with any exceptions (expedited methods, debit funding) listed on Kalshi's fee page. There are no account maintenance or inactivity fees comparable to a brokerage.

How should fees change my trading decisions?

Treat the round-trip cost — fee in, fee or spread out — as a hurdle your edge must clear. A trade that's positive expected value by 2 cents per contract but costs 3 cents round-trip is a losing trade. This bites hardest on high-frequency, small-edge strategies and near-50-cent contracts where fees peak.