Polymarket fee calculator
Enter the share price in cents and the number of shares. You get the fee on a Polymarket US sports market, what the order really costs, and the odds it pays once the fee is counted, so you can compare it with a sportsbook line.
How the fee works on Polymarket US sports markets
fee ≈ 0.0695 × shares × price × (1 − price)
Price is in dollars, so 50¢ is 0.50. Like Kalshi's, the fee is largest at 50¢ and shrinks toward the ends. Each share pays $1 if it wins. The figures here round the fee up to the cent, the safe side when you compare prices.
Fees and real odds for 100 shares
| Price | Fee | Total cost | Odds after fee | Fee as share of cost |
|---|---|---|---|---|
| 10¢ | $0.63 | $10.63 | +841 | 5.93% |
| 20¢ | $1.12 | $21.12 | +373 | 5.30% |
| 30¢ | $1.46 | $31.46 | +218 | 4.64% |
| 50¢ | $1.74 | $51.74 | -107 | 3.36% |
| 70¢ | $1.46 | $71.46 | -250 | 2.04% |
| 90¢ | $0.63 | $90.63 | -967 | 0.70% |
A 50¢ share looks like even money (+100), but after the fee it pays like -107, about the same as Kalshi and better than the -110 a sportsbook usually charges. For Kalshi's version see the Kalshi fee calculator.
Polymarket US and international Polymarket
The fee above is the one on Polymarket US game markets. The international site has charged no trading fee on most markets. Fees can change; Polymarket's own fee page has the current rates.
Questions
How much is the Polymarket fee on sports?
On Polymarket US game markets, about 0.0695 x shares x price x (1 - price). For 100 shares at 50 cents that is about $1.74.
What odds does a 50 cent Polymarket share pay after fees?
100 shares cost $50 plus about $1.74 and pay $100: decimal 1.933, or about -107.
Is Polymarket cheaper than Kalshi?
On sports the fees are nearly the same: 0.0695 against Kalshi's 0.07. Compare the prices themselves, which differ more than the fees.
Related
Updated 2026-10-26