Prediction Market Fee Calculator

Trading fees eat into your returns on every prediction market trade — and the platforms make comparison genuinely hard by charging in incompatible ways: probability-weighted formulas (Kalshi, Polymarket), flat per-contract fees (OG, Underdog, Fanatics), a percentage of payout (FanDuel), and a percentage of winnings charged only when you profit (ProphetX). This calculator shows the exact cost on seven platforms side by side for the trade you’re planning.

Last updated: July 2026 — added OG, ProphetX, Underdog, and Fanatics Markets; updated Polymarket to its current US fee formula and corrected FanDuel’s fee basis to potential payout.

Prediction Market Fee Calculator


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Order Type


Taker = you accept an existing price. Maker = you set your own price and wait for a fill. Maker/taker pricing applies on Kalshi and Polymarket; the other platforms charge the same fee either way.

Adjust the inputs above to compare fees across platforms.

Fees calculated from each platform’s published fee schedule as of July 2026. ProphetX charges fees only on net winnings — its card shows what you’d pay if the trade wins, and it is excluded from the “lowest cost” badge because the fee is contingent. OG’s fee shown is the position-open fee; closing early costs another 2¢/contract, while holding to settlement is free. Kalshi S&P 500 / Nasdaq-100 contracts use a reduced multiplier not reflected here. Deposit surcharges are not included. Novig charges no commission but operates as a sweepstakes (see note below). See our methodology for how we verify fee data.

How Fees Work on Each Platform

Every prediction market charges trading fees, but the structures differ enough that the cheapest platform changes with the contract price, your order type, and whether you win. Here’s each platform’s published schedule as of July 2026.

Kalshi

Probability-weighted formula, confirmed in Kalshi’s July 7, 2026 fee schedule: taker fee per contract = 0.07 × Price × (1 − Price), rounded up to the nearest cent. Fees peak around 1.75¢ per contract at 50¢ and shrink toward both extremes. Makers pay 25% of the taker rate. S&P 500 and Nasdaq-100 contracts use a halved multiplier. Deposits: ACH free; 2% surcharge on debit/Apple/Google Pay. Full details in our Kalshi review.

Polymarket (US platform)

Same formula shape as Kalshi with a smaller coefficient: taker fee per contract = 0.05 × Price × (1 − Price), capped at $1.25 per 100 contracts. Makers don’t just trade free — they earn a rebate of 25% of the taker fee. No deposit or withdrawal fees. iOS-only for US users as of July 2026. Full details in our Polymarket review.

OG

Flat 2¢ per $1 contract to open a position and another 2¢ if you close early — but $0 at settlement, win or lose. Larger $10/$100 contract denominations carry additional exchange and technology fees. Deposits: bank transfers free; 1.49% on debit cards, 1.99% on PayPal. Full details in our OG review.

ProphetX

The outlier: 2% of net winnings per market, charged only when you profit. Lose the trade, pay nothing. Win a parlay, pay 0%. A VIP tier drops the rate to 1.5%. No deposit or withdrawal fees on any method. For traders who win consistently, this is the cheapest structure in the field; for everyone else it’s still hard to beat, because losing trades are free. Full details in our ProphetX review.

FanDuel Predicts

A flat 2% of potential payout — and since every contract pays $1.00 if it wins, that works out to 2¢ per contract regardless of price (a $95 potential payout costs $1.90). No maker/taker distinction; the fee also applies when you cash out early. Zero deposit fees on every method including PayPal and Venmo. Full details in our FanDuel Predicts review.

Underdog Predict

Flat ~2¢ per contract with no deposit or redemption fees. One quirk worth knowing: a $4/month inactivity fee applies after 18 months of no account activity. Full details in our Underdog Predict review.

Fanatics Markets

A price-dependent per-contract table (official schedule effective June 29, 2026): a flat 2.4¢ per contract for prices between 20¢ and 80¢, tapering toward the extremes (about 0.4¢ at 1¢, 0.8¢ at 99¢). Charged per execution — on buys and on sells — with order totals rounded up to the next cent and a 1¢ minimum. ACH deposits free; up to 2% on debit/Apple Pay; withdrawals free. Full details in our Fanatics Markets review.

What about Novig and ADI Predictstreet?

Novig charges no commission at all — but it currently operates as a sweepstakes (dual-currency model), so its costs aren’t directly comparable to regulated exchange fees; in thin markets an effective 1–4% spread can be embedded in prices where Novig seeds liquidity. Its CFTC-regulated exchange, approved June 2026, is expected to launch by end of summer — we’ll add it to the calculator when its exchange fee schedule publishes. ADI Predictstreet publishes no verifiable fee schedule, so we exclude it entirely. See our Novig review and ADI Predictstreet profile.

When Fees Matter Most

  • High-probability contracts: This is where the structures diverge hardest. At 90¢, Kalshi charges ~0.63¢ and Polymarket ~0.45¢ per contract, while the flat-fee platforms (OG, FanDuel, Underdog) still charge 2¢ and Fanatics ~1.9¢. Formula platforms win big at the extremes.
  • High volume: If you trade 50+ contracts a week, the platform gap compounds to hundreds of dollars a year. Maker orders on Polymarket actually pay you; maker orders on Kalshi cost a quarter of taker rates.
  • If you win more than you lose: ProphetX’s winnings-only fee means your losing trades subsidize nothing. Profitable sports traders should run their actual win rate against the entry-fee platforms.

For most casual traders, fees are secondary to market selection, regulation, and funding options. Our platform rankings weigh fees alongside eight other categories.

Common Questions

Which prediction market has the lowest fees?

For entry fees on most contract prices, Polymarket US — its taker formula caps at 1.25¢ per contract and makers earn rebates. For profitable sports traders, ProphetX can be cheapest overall since fees apply only to winnings. FanDuel Predicts is usually the most expensive at 2¢ per contract on every order.

How are Kalshi fees calculated?

Taker fee per contract = 0.07 × Price × (1 − Price), rounded up to the nearest cent — about 1.75¢ at 50¢, under a penny beyond 85¢ or below 15¢. Makers pay 25% of that. Confirmed against Kalshi’s July 7, 2026 fee schedule.

Does Polymarket charge fees?

The US platform charges takers 0.05 × Price × (1 − Price) per contract (max $1.25 per 100 contracts) and pays makers a 25% rebate. Deposits and withdrawals are free. The global platform charges near zero on most markets.

What does FanDuel Predicts charge per trade?

2% of potential payout — effectively 2¢ per contract at any price, on every order type, including early cash-outs. Deposits are free on all methods.

How do ProphetX fees work?

2% of net winnings per market, charged only when you profit. Losing trades pay nothing; winning parlays pay 0%; VIPs pay 1.5%. No deposit or withdrawal fees.

Do prediction markets charge deposit fees?

Bank transfers are free everywhere. Card-based deposits often aren’t: Kalshi adds 2% on debit/Apple/Google Pay, OG charges 1.49% on debit and 1.99% on PayPal, and Fanatics up to 2% on debit/Apple Pay. FanDuel Predicts and ProphetX charge no deposit fees at all (ProphetX doesn’t accept cards).

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