How to read prediction market prices as odds

Price = probability

Most prediction market contracts are binary: they pay $1 if the event happens and $0 if it doesn’t. That makes the price easy to read. If a contract trades at 62¢, traders are collectively willing to pay 62¢ for a chance at $1, which implies a probability of about 62%.

That’s also why prediction markets quote prices in cents rather than odds. But if you’re used to sportsbooks, or you want to compare the two, it helps to translate. Our ranking of the best prediction markets in the US covers where you can trade these contracts; this guide covers how to read them.

The conversion formulas

For a contract priced at p (in dollars, so 40¢ = 0.40):

You don’t have to do this by hand: enter the probability in our free odds calculator and it shows the American, decimal and fractional equivalents.

Conversion table

These are fee-free figures. “Profit on $100 staked” means spending $100 on contracts at that price — at 25¢ that’s 400 contracts, which pay $400 if they win.

Yes and No are two sides of the same bet

In a market such as “Will the Chiefs win?”, buying Yes at 40¢ is the same position as betting the Chiefs at +150. Buying No at 60¢ is betting against them at -150. Because the two sides of a contract pay $1 between them, their prices add up to roughly $1 — in practice slightly more, because of the spread (see below).

That’s also how you exit early. You can sell the contracts you hold, and on some platforms — Interactive Brokers’ ForecastEx, for example — you close a position by buying the opposite side.

Adding fees and the spread

The odds you actually get depend on what you pay, not just the quoted price:

1. Start from the ask — the price you can buy at right now — not the last traded price.
2. Add the trading fee. On Kalshi, the taker fee on a 40¢ contract is 0.07 × 0.40 × 0.60 = 1.68¢, so each contract really costs 41.68¢.
3. Convert the total. 1 ÷ 0.4168 = 2.40 in decimal odds, or about +140 instead of +150.

The fee matters most near 50¢ and very little near 1¢ or 99¢. The spread matters most in thin markets: if Yes can be bought at 42¢ but only sold at 38¢, you give up 4¢ on a round trip before fees. Our prediction market fees guide compares every platform’s fees.

Going the other way: odds to prices

To compare a sportsbook line with a prediction market, turn the odds into a price:

• -110 → 110 ÷ (110 + 100) = 52.4¢
• +150 → 100 ÷ (150 + 100) = 40¢

If a sportsbook offers -110 on a team and a prediction market lets you buy the same outcome at 50¢ plus a small fee, the prediction market is the better price. Our comparison of prediction markets vs sportsbooks goes into when each makes sense.

Finding value

A price is only a good buy if you think the true probability is higher. Suppose a contract costs 45¢ and you estimate the chance at 52%:

• Cost per contract with Kalshi’s taker fee: 45¢ + 1.73¢ = 46.73¢
• Expected payout: 52% × $1 = 52¢
• Expected value: 52¢ − 46.73¢ = +5.27¢ per contract, or about $5.27 per 100 contracts

That’s a positive expected value — but only if your 52% is right. Our EV calculator runs the same math for any price and probability.

Why the CFTC warns about odds displays

In August 2026 the CFTC reminded exchanges to show clear pricing and warned that displaying event contracts in sportsbook-style American odds is likely to mislead users, because it can obscure fees and the fact that you’re trading against other people rather than a bookmaker. Converting prices yourself is fine for comparison — just remember to include the fee and the spread.

The bottom line

Read a prediction market price as a probability, convert it with 1 ÷ price when you want decimal odds, and always include fees before comparing it with a sportsbook. When you’re ready to trade, compare the platforms in our ranking of the best US prediction markets.