Kalshi vs Polymarket fees, at your price

Both venues charge more when a contract is near 50¢ and almost nothing near the extremes — the fee is a curve, not a flat rate. The headline numbers ("7%" vs "6%") are the coefficients in that curve. Enter a price and a size:

The formulas, as published

• Kalshi taker: 0.07 × price × (1 − price) per contract, rounded up to the cent per contract here (the venue rounds per order, so this is the conservative reading). Maker fee is 25% of the taker fee. A higher multiplier applies to some premium categories such as crypto.
• Polymarket US taker: 0.06 × price × (1 − price) per share, per the schedule effective July 1, 2026. Maker fee coefficient 0.0125.
• Polymarket (global): fees are set per market and published on each market; economics markets have carried a 0.05 taker rate. Not available to US accounts.

At a glance

Both peak at 50¢: 1.75¢ (Kalshi, shown rounded up to 2¢ per contract) vs 1.5¢ (Polymarket US). At 90¢ they are 0.63¢ (rounded to 1¢) and 0.54¢. Deposits, withdrawals, and any crypto on-ramp costs are separate and not modeled here.

Sources

• Kalshi Help Center — Fees
• Kalshi fee schedule (July 2026 PDF)
• Polymarket US — Fee Schedule