4 min read · Updated June 29, 2026
Polymarket fees explained
Key takeaways
- › Polymarket charges no platform fee on trades.
- › Gas on Polygon is typically under a cent.
- › On-ramp costs (buying USDC) are the biggest line item.
- › Spread is your effective cost — thin markets cost more.
- › Off-ramp back to USD has bridge/exchange fees.
The full cost stack
- On-ramp: Buying USDC on a fiat ramp costs 0.5–4% depending on provider.
- Bridge (if needed): Moving USDC to Polygon — usually a few cents.
- Gas: Fractions of a cent per Polymarket trade.
- Spread: The gap between best bid and best ask — this is your actual trading cost.
- Off-ramp: Selling USDC back to USD — 0.5–2% on most exchanges.
When Polymarket is cheaper than Kalshi
On deep, liquid markets (presidential election, Fed decision, World Cup winner) the spread is usually 1¢ or less, and the zero platform fee makes Polymarket the cheapest option for size. On thin or obscure markets the spread can blow out and Kalshi's transparent per-contract fee wins.
Round-trip cost — Polymarket vs Kalshi
| Cost line | Polymarket | Kalshi |
|---|---|---|
| Platform trading fee | 0% | ~1.75¢/contract @ $0.50 |
| Deposit | On-ramp 0.5–4% USDC | Free ACH / debit |
| Withdrawal | Off-ramp 0.5–2% | Free ACH |
| Gas / network | Fractions of 1¢ | None |
| Tax reporting | Self-report | 1099 issued |
Polymarket is cheapest per trade for size on deep books once you're already in USDC. Kalshi is cheapest end-to-end for U.S. bank-to-bank trading, including for Florida residents.
Florida angle
Polymarket restricts U.S. residents, so most Florida traders won't use it as a primary account regardless of the fee advantage. If you're in FL and want the cheapest legal round-trip from a U.S. bank, Kalshi is the honest answer — no state income tax, free ACH, and no on-ramp friction.
Start trading in 2 minutes
Both platforms are free to sign up. Kalshi is CFTC-regulated USD. Polymarket settles in USDC.
Play responsibly
Prediction markets are real-money trading and you can lose your full stake. We recommend 21+. If trading stops feeling fun, call 1-800-GAMBLER or text 988.
Reviewed by Catie Di Stefano. Every guide follows our editorial standards & review methodology. Affiliate links are disclosed under our affiliate disclosure.