5 min read · Updated June 28, 2026
Kalshi fees explained

Key takeaways
- › Trading fee formula: round(0.07 × contracts × price × (1 − price)) cents per fill.
- › Maximum fee per contract is ~1.75¢, hit at $0.50.
- › Fees drop toward zero as price approaches $0.00 or $1.00.
- › ACH and debit deposits free; ACH withdrawals free; wire withdrawals have a small fee.
- › Reported net of fees on your 1099 at year-end.
The trading fee formula
Per fill, Kalshi charges: round(0.07 × C × P × (1 − P)) in cents, where C is contracts filled and P is the fill price between 0 and 1.
The shape: zero at the extremes ($0 or $1), peak at $0.50. That's why pros price-shop into mispricings — fees compress when you trade tails.
Worked examples
| Trade | Cost | Fee |
|---|---|---|
| 100 contracts @ $0.50 | $50.00 | ~$1.75 |
| 100 contracts @ $0.10 | $10.00 | ~$0.63 |
| 100 contracts @ $0.90 | $90.00 | ~$0.63 |
| 1,000 contracts @ $0.50 | $500.00 | ~$17.50 |
Deposit and withdrawal costs
- ACH deposits: free, 1–3 business days.
- Debit card deposits: free, instant.
- Wire deposits: free on Kalshi's side (your bank may charge).
- ACH withdrawals: free, 1–3 business days.
- Wire withdrawals: small platform fee.
Kalshi fees vs Polymarket — cost comparison
| Trade | Kalshi | Polymarket |
|---|---|---|
| $50 fill @ $0.50 | ~$0.88 | $0 platform + ~1¢ spread |
| $500 fill @ $0.50 | ~$8.75 | $0 platform + spread |
| $500 fill @ $0.10 | ~$3.15 | $0 platform + spread |
| Deposit $500 | Free ACH | On-ramp 0.5–4% USDC |
| Withdraw $500 | Free ACH | Off-ramp 0.5–2% + bridge |
Kalshi's fee is transparent and USD-native. Polymarket's zero platform fee is only truly zero if you already hold USDC on Polygon — on/off-ramp costs are the real hidden line.
Florida angle
Florida has no state income tax, so the only tax on Kalshi gains is federal — reported on the 1099 Kalshi issues automatically. Free ACH deposits and withdrawals make Kalshi cheaper end-to-end for a Florida trader than any crypto-based alternative once on-ramp costs are counted.
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.