Kalshi and Polymarket US converge on fees at midpoint prices

According to RotoGrinders, Kalshi and Polymarket US charge nearly identical trading fees: about $1.75 per 100 contracts priced at 50 cents. The comparison was verified on November 4, 2026.

Similar US fees, different global structure

Kalshi’s per-contract fee reaches its highest level on contracts priced near 50 cents, according to RotoGrinders. Polymarket US now charges essentially the same amount, leaving little fee difference between the two US platforms at that price.

The comparison does not extend to Polymarket’s separate global exchange. According to RotoGrinders, that venue applies category-based fees to takers while charging makers nothing—a different structure from the US fee comparison.

Access restrictions also align

Both US apps are unavailable in the same nine states, according to RotoGrinders. The supplied summary does not identify those states or provide a broader breakdown of fees across contract prices.

What it means for prediction markets

• Midpoint costs are closely matched: At 50 cents, the reported fee is about $1.75 per 100 contracts on either US platform. That comparison alone does not establish equal costs at every price.
• The venue distinction matters: Polymarket US and Polymarket’s global exchange have different fee structures; the global exchange distinguishes between takers and makers.
• Availability is a shared constraint: Switching between the two US apps does not resolve access restrictions in the nine states where both are unavailable.