Kalshi Fees: Why the Cost Peaks Near 50 Cents

The most expensive place to trade on Kalshi is the coin-flip in the middle. Kalshi charges a variable trading fee that peaks when a contract trades near 50 cents and gets smaller as the price moves toward either 1 cent or 99 cents. It is not a flat percentage and not a fixed dollar amount, so the same 100 contracts can cost very different amounts depending on the price you buy at.

That single fact trips up most people reading their trade confirmations. The fee on a market sitting around 50 cents is the largest fee Kalshi will charge you, and the cost falls away as the market grows more confident in one direction. Below is the curve, the math, and the exact cost on a real order.

Key takeaways

• Kalshi's trading fee follows a curve that peaks at a 50 cent contract price and shrinks toward both 1 cent and 99 cents.
• The fee is calculated per contract using the formula 0.07 x C x P x (1 - P), where C is the number of contracts and P is the price in dollars.
• Because of the P x (1 - P) term, a 50 cent trade costs roughly seven times more in fees than a 10 cent or 90 cent trade of the same size.
• Kalshi rounds the fee up to the next cent, so tiny orders pay a slightly higher effective rate.
• Some Kalshi products carry their own separate fee schedule, so the general formula is a baseline, not a universal rule.

The fee curve, on 100 contracts

Kalshi publishes its fee schedule in its official fee schedule. The general trading fee is:

fee = round up ( 0.07 x C x P x (1 - P) )

C is the number of contracts, P is the price per contract in dollars. The P x (1 - P) factor creates the curve. That expression is largest at P = 0.50 (where it equals 0.25) and drops toward zero as P approaches 0 or 1.

Here is what that means for an order of 100 contracts at five different prices:

Read the middle column and the shape is obvious. The fee is symmetric around 50 cents. Buying "yes" at 90 cents costs the same fee as buying "no" at 10 cents, because both sides of the same market are mirror images. The most expensive place to trade is the toss-up in the middle.

Why the curve is shaped this way

The fee is proportional to P x (1 - P), which is the variance of a single yes/no outcome at probability P. When a market is near 50/50, uncertainty is at its maximum and so is the fee. As the market resolves toward near-certainty, the fee shrinks toward nothing. Practically, the cost of trading long-shot or near-locked markets is low, and the cost of trading genuine coin-flips is high.

What this costs relative to your stake

Fees look small in absolute dollars, but the ratio to your capital tells a sharper story. On the same 100 contracts:

Here the picture flips. As a share of the money you put down, the fee is heaviest on cheap long-shot contracts, even though the absolute fee is smallest there. A 10 cent contract costs you 6.3% of your stake in fees, while a 90 cent contract costs 0.7%. Where fees hurt most depends on whether you measure absolute dollars (peaks at 50 cents) or percentage of capital deployed (heaviest at low prices). Both are true at once, and both matter when you size a position.

Rounding, and why small orders pay more

Kalshi rounds the calculated fee up to the next whole cent. On large orders this is negligible. On a one or two contract order it can meaningfully raise your effective rate, because a raw fee of $0.0175 still gets rounded up to a full cent. If you place many tiny orders instead of one larger order, you pay the rounding penalty repeatedly. Consolidating order size reduces the drag from rounding.

Fees Kalshi does not charge, and ones it might

Kalshi's published schedule lists no separate maker or taker distinction on its general trading fee and no deposit fee for standard funding methods, though it does apply a fee on certain deposit types. It also settles contracts at $1.00 or $0.00 with no separate settlement fee on the general schedule. The important caveat is that specific product families can carry their own pricing. Kalshi's fee schedule is the authoritative source, and it is updated over time, so treat the 0.07 multiplier as the current general baseline rather than a permanent constant. If you are modeling costs for a strategy, pull the live schedule rather than a number from a blog.

Comparing fee-adjusted activity across venues

Once you compare what traders actually pay across prediction markets, the fee is only one field among several you need lined up. To compare realized cost or open interest on Kalshi against an onchain venue like Polymarket, the same trade has to resolve to consistent fields: market, outcome, contract price, size, notional value, timestamp and fee. Kalshi is a centralized, CFTC-regulated exchange whose records live off-chain, while Polymarket settles onchain, so the two sit in different data shapes.

Allium standardizes both, mapping Kalshi's records and onchain prediction market activity into common schemas so a price, a size and a notional value mean the same thing on either side. Teams that need the underlying records can work from Allium's Kalshi tables and its broader prediction market datasets. For the mechanics of a Kalshi trade end to end, read how Kalshi works from order to payout, and for the cross-venue comparison, comparing Polymarket and Kalshi open interest.

Frequently asked questions

What is the formula for Kalshi's trading fee?

The general trading fee is 0.07 x C x P x (1 - P), rounded up to the next cent, where C is the number of contracts and P is the price per contract in dollars. Because of the P x (1 - P) term, the fee peaks at a 50 cent price and shrinks toward 1 cent and 99 cents.

Why is the fee highest on 50 cent contracts?

The fee is proportional to P x (1 - P), which is largest when P equals 0.50. That expression represents the variance of a yes/no outcome, which is at its maximum when the market is a genuine coin-flip and falls toward zero as the outcome becomes near-certain.

How much are Kalshi fees on a $100 trade?

It depends on the contract price, not the dollar amount alone. 100 contracts at 50 cents (a $50 position) carries roughly a $1.75 fee, while 100 contracts at 90 cents (a $90 position) carries about a $0.63 fee. Cheaper long-shot contracts cost less in absolute fees but more as a percentage of your stake.

Does Kalshi charge a fee to withdraw or settle?

Kalshi's general fee schedule does not list a separate settlement fee, and contracts resolve at $1.00 or $0.00. Some deposit methods carry a fee. Always check Kalshi's current published fee schedule, since terms are updated over time and specific products can differ.

Do all Kalshi markets use the same fee?

No. The 0.07 multiplier is the general baseline, but certain product families, including some financial index event contracts, have their own separate fee schedules. The authoritative reference is Kalshi's official fee schedule document, which lists per-product pricing.

Does order size change my Kalshi fee rate?

Indirectly, through rounding. Kalshi rounds each fee up to the next cent, so many tiny orders pay the rounding penalty repeatedly and end up with a higher effective rate than one consolidated order of the same total size.