Polymarket: commission, effective odds and arbitrage
- Commission model
- net winnings
- Rate (placeholder)
- 2%
- Even money after commission
- 1.980
- Lay bets
- no
| Side | Price | Decimal | American | Fractional | Probability |
|---|---|---|---|---|---|
| YES | 63¢ | 1.587 | -170 | 37/63 | 63.00% |
| NO | 38¢ | 2.632 | +163 | 31/19 | 38.00% |
- Spread (YES + NO − 100¢)
- 1.00%
YES is 1.587 decimal or -170 American
Polymarket is a prediction market that charges 2% commission on net winnings. That changes what every price is worth: even money (2.00) becomes 1.980 after commission, and the win rate you need to break even rises to 50.51%. Everything below is computed at that rate.
Polymarket is a prediction market where outcomes trade as shares priced between 0 and 1 dollar. A share pays $1.00 if its outcome happens, so the price is the probability. Fees have changed over time and differ by market category; gas and withdrawal costs are ignored on this site.
How Polymarket commission works
Commission on net winnings is charged only when you win, as a percentage of the profit. The
effective odds are 1 + (odds − 1) × (1 − rate). Losing bets pay nothing extra, so the loss side
of the bet is unchanged. This is the model most exchanges use, and it means favourites lose less
value to commission than outsiders do: a 1.20 shot at 2% is barely dented,
while a 10.00 shot loses 2% of a much larger profit.
| Odds | Effective | American | Break-even | Net profit on 100 |
|---|---|---|---|---|
| 1.50 | 1.490 | -204 | 67.11% | 49.00 |
| 1.91 | 1.892 | -112 | 52.86% | 89.18 |
| 2.00 | 1.980 | -102 | 50.51% | 98.00 |
| 2.50 | 2.470 | +147 | 40.49% | 147.00 |
| 3.00 | 2.960 | +196 | 33.78% | 196.00 |
| 5.00 | 4.920 | +392 | 20.33% | 392.00 |
| 10.00 | 9.820 | +882 | 10.18% | 882.00 |
Backing at a bookmaker, laying at Polymarket
Polymarket does not offer lay bets, so the usual bookmaker-versus-exchange hedge is not available. The converter above turns a YES or NO price in cents into decimal and American odds and an implied probability, which is the quickest way to compare a Polymarket market with a bookmaker line. For a two-way arbitrage with Polymarket on one leg and a bookmaker on the other, open the arbitrage calculator pre-set to Polymarket; it applies Polymarket's fee to its leg.
Using Polymarket prices to find fair odds
Exchange prices are set by traders rather than by a bookmaker's margin, so after commission they are often close to the fair line. To use them that way, take both sides of a market, remove what little overround remains with the devig calculator pre-set to Polymarket, and compare the result with the bookmaker prices you are offered. A bookmaker price above the fair line is value.
Comparing Polymarket with other venues
The pairs listed at the bottom of this page each open an arbitrage calculator with Polymarket on one leg and another venue on the other, commission applied to both. They are the quickest way to see how much two venues must disagree before a position pays.
Regions and verification
Polymarket lists global among its markets. Availability, licensing and commission all differ by country; the figures on this page are arithmetic, not a statement about what you can access where you live.
Frequently asked questions
What commission does Polymarket charge?
The placeholder rate on this page is 2% on net winnings, last reviewed 2026-09-09. Rates vary by country, product and discount tier; confirm the figure in your own account.
What are the effective odds of 2.00 at Polymarket?
After 2% commission on net winnings, even money (2.00) is worth 1.980, and the break-even win rate rises to 50.51%.
Can I lay bets at Polymarket?
No. Polymarket does not offer lay bets, so hedges against a bookmaker use a back bet on the other outcome instead.
Is Polymarket a good source of fair odds?
Prices set by traders carry a small overround, so after removing it they are close to a fair line. Remember to account for commission when comparing with a bookmaker price you will actually take.
Does commission apply to every bet?
Most venues charge on the net result of a market rather than on each bet, so offsetting bets in the same market share one commission charge. This site models one bet at a time.