Prediction market fee calculator: what an order really costs
Enter the price and the number of contracts. See the estimated fee, your all-in cost per contract and the hit rate you need to break even after fees.
Your order
7% is a common published rate for taker orders. Maker orders and some markets are charged less or nothing, so check your exchange's schedule.
Readout
fee = rate × contracts × P × (1 − P), rounded up to the cent
Worked example
You buy 100 contracts at 30¢ at a 7% fee rate. The fee is 0.07 × 100 × 0.30 × 0.70 = $1.47. The contracts cost $30.00, so you pay $31.47 in all, or 31.47¢ per contract.
A contract pays $1 if it settles yes, so you need it to settle yes about 31.5% of the time to break even. Without the fee, you'd need 30%.
Fees at every price
Estimated fee per contract at a 7% rate. Because the fee follows P × (1 − P), it is largest at 50¢ and smallest near the ends, but cheap contracts pay the most as a share of their price.
| Price | Fee per contract | Fee as share of price | Break-even after fee |
|---|---|---|---|
| 10¢ | 0.63¢ | 6.3% | 10.63% |
| 20¢ | 1.12¢ | 5.6% | 21.12% |
| 30¢ | 1.47¢ | 4.9% | 31.47% |
| 40¢ | 1.68¢ | 4.2% | 41.68% |
| 50¢ | 1.75¢ | 3.5% | 51.75% |
| 60¢ | 1.68¢ | 2.8% | 61.68% |
| 70¢ | 1.47¢ | 2.1% | 71.47% |
| 80¢ | 1.12¢ | 1.4% | 81.12% |
| 90¢ | 0.63¢ | 0.7% | 90.63% |
Single-contract figures before rounding. Orders are rounded up to the cent, so small orders can pay slightly more per contract.
Questions
How are prediction market fees calculated?
Many exchanges charge a fee that scales with rate × contracts × P × (1 − P), where P is the price in dollars, rounded up to the cent. At a 7% rate, 100 contracts at 30¢ cost about $1.47 in fees.
Where are prediction market fees highest?
In cents, the fee is highest at 50¢, where P × (1 − P) peaks: 1.75¢ per contract at a 7% rate. As a share of the price, it is highest on cheap contracts: about 6.3% at 10¢.
How do fees change my break-even?
Your break-even hit rate equals your all-in cost per contract in cents. A 30¢ contract with a 1.47¢ fee needs to settle yes 31.47% of the time to break even.
Do maker orders pay fees?
It depends on the exchange and the market. Some charge makers less or nothing. This calculator uses the rate you enter, so set it to match your exchange's schedule.
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