Kalshi Fees Explained: The Full 2026 Fee Formula

Buy 100 YES contracts on Kalshi at $0.50 and the fee is $1.75. Buy the same 100 contracts at $0.90 and the fee drops to $0.63 — less than half, for the same trade size. Kalshi fees aren't a flat percentage; they follow a formula that penalizes trading near the coin-flip price and rewards trading near the extremes. Here's the exact math, official source, and where it actually bites.

The formula

Kalshi's general taker fee is:

Fee = round_up(0.07 × C × P × (1 − P))

where C is the number of contracts and P is the price in dollars (between $0.01 and $0.99). The result rounds up to the next cent. A shorthand way to think about it: 7 cents times the number of contracts, times price, times (1 minus price). This is Kalshi's published general fee schedule — always confirm the live numbers at kalshi.com/fee-schedule, since some contract types run different rates.

Why the fee peaks at 50 cents

The term P × (1−P) is a parabola that peaks when P = 0.50, where it equals 0.25 (0.50 × 0.50). Move away from 50 cents in either direction and that product shrinks — at $0.90, it's 0.90 × 0.10 = 0.09, less than half of 0.25. That's the entire mechanism behind why fees are highest at the coin-flip price and taper toward the $0.01/$0.99 extremes: the formula is directly proportional to how much uncertainty is priced into the contract, and a 50-cent price represents maximum uncertainty.

Practically, this means the same dollar amount of risk costs different amounts to put on depending on where the price sits. Buying $50 worth of contracts at $0.50 (100 contracts) costs $1.75 in fees — 3.5% of the position size. Buying $50 worth of contracts at $0.90 (about 55 contracts) costs roughly $0.35 in fees, under 1% of the position size. Traders building strategies around near-certain outcomes (contracts trading in the $0.90+ or $0.10- range) pay meaningfully less in fees per dollar deployed than traders working coin-flip markets — one more reason toss-up contracts need a bigger genuine edge to be worth trading.

Worked examples

Example 1: 100 contracts at $0.50

round_up(0.07 × 100 × 0.50 × 0.50) = round_up(0.07 × 100 × 0.25) = round_up(1.75) = $1.75. This is the maximum possible fee on a 100-contract order under the general schedule — it can't get more expensive than this per 100 contracts, regardless of price.

Example 2: 100 contracts at $0.90

round_up(0.07 × 100 × 0.90 × 0.10) = round_up(0.07 × 100 × 0.09) = round_up(0.63) = $0.63. Less than half the fee of the 50-cent example, on the same 100-contract size.

Fee by price point

Price (P)	P × (1−P)	Fee per 100 contracts (taker)
$0.10 / $0.90	0.09	$0.63
$0.25 / $0.75	0.1875	$1.32
$0.40 / $0.60	0.24	$1.68
$0.50	0.25	$1.75 (maximum)

Maker vs. taker rates

Kalshi's maker fee — charged when your resting limit order gets filled rather than crossing the spread — is 25% of the taker rate. At the 50-cent maximum, that works out to roughly $0.44 per 100 contracts versus $1.75 for a taker. This discount is the core economic incentive behind posting liquidity instead of taking it, and it's why market-making strategies (see Kalshi trading strategies, strategy #4) specifically target the maker rate rather than paying full taker fees on every trade.

What the formula doesn't cover

The 7% formula is Kalshi's general schedule, not a universal one. Certain contract types — including some S&P 500 and Nasdaq range markets — carry different fee rates. If you're trading outside the standard political, economic, weather, or sports categories, check the specific market's fee terms before assuming the standard formula applies. The published schedule at kalshi.com/fee-schedule is the authoritative source and gets updated as Kalshi adjusts pricing.

Round-trip cost, not just entry cost

The fee examples above cover one side of a trade. If you enter and exit before settlement — buying YES at $0.50 and selling it back at $0.55 rather than holding to resolution — you pay the taker fee twice, once on each leg, assuming both are taker orders. On 100 contracts entering and exiting near the 50-cent zone, that's roughly $3.50 in fees round-trip, which is a real number to subtract from a short-term price-movement trade before it's genuinely profitable. Holding to settlement instead of round-tripping only incurs the entry fee, since settlement itself — the $1 or $0 payout — isn't a taxable trading event on the fee schedule.

How Kalshi's structure compares to Polymarket's

Polymarket's 2026 fee model works differently: category-based taker fees ranging roughly $0.75 to $1.80 per 100 shares depending on category (sports, politics, crypto, etc.), with makers never charged and geopolitical/world-event markets fee-free entirely. Kalshi's formula is uniform across most contract types and scales continuously with how close the price sits to 50 cents, rather than varying by category. Neither structure is simply cheaper — a Kalshi trade at $0.90 can cost less than a Polymarket crypto-category trade at the same price, while a Kalshi trade at $0.50 can cost more than a Polymarket sports-category trade. The full side-by-side breakdown, including Polymarket's own fee mechanics, is in Polymarket fees explained.

Why this matters for strategy

Fee drag is the first filter any trade idea has to survive. A mispricing that looks like a two-cent edge at a 50-cent price needs to clear $1.75 per 100 contracts just to break even on the fee — a much higher bar than the same two-cent edge near $0.10 or $0.90, where the fee is closer to $0.63. This is why cross-venue arbitrage against Polymarket, covered in Kalshi arbitrage, is far more sensitive to price level than it might first appear, and why the general math behind fee-adjusted edges is worth understanding on its own — see arbitrage fee math for the cross-venue version of this same calculation. For the mechanics behind how these prices form in the first place, see the Kalshi trading guide.

Running this math by hand on every candidate trade doesn't scale once you're watching more than a handful of markets. PolyMarketMaker's terminal applies Kalshi's exact fee formula to live order-book data automatically, so the price you see quoted already accounts for what a fill will actually cost after fees — useful both for spotting genuine mispricings and for sizing a market-making quote correctly. PolyMarketMaker — Simulation $149/mo, Live Trading $299/mo.

FAQ

What is Kalshi's fee formula?

The general taker fee is round_up(0.07 × contracts × price × (1−price)), rounded up to the next cent, with price between $0.01 and $0.99.

What is the maximum Kalshi fee?

$1.75 per 100 contracts, occurring at exactly a $0.50 price, where price × (1−price) hits its peak value of 0.25.

How much less do Kalshi makers pay in fees?

Makers pay 25% of the taker rate — about $0.44 per 100 contracts at the 50-cent maximum, versus $1.75 for a taker.

Do all Kalshi contracts use the same fee formula?

No. The 7% formula is the general schedule; some contract types, including certain S&P 500 and Nasdaq range markets, carry different rates. Check kalshi.com/fee-schedule for the specific market.

This article is for educational purposes only and is not financial advice. Trading involves risk of loss.