Guide
Kalshi vs sportsbook odds: how to compare a prediction market price
To compare Kalshi vs sportsbook odds, read the Kalshi price you would pay in cents as a win chance (39 cents is 39%), add the trading fee, and set it against the sportsbook's no-vig chance for the same outcome: if your cost after the fee is below the fair chance, the Kalshi side is the better bet.
We open live odds right after you sign up.
Free during beta. No card. Google or email, about a minute.
By the Betwatch team. Published Nov 2, 2026, updated Nov 10, 2026.
Worked example: Celtics vs Knicks on Kalshi and at a sportsbook
A sportsbook has the Celtics at -160 and the Knicks at +135. Those are 61.5% and 42.6%, which add to 104.1%. Divide each by 104.1% and the fair chances are 59.1% and 40.9%, or about -145 and +145.
On Kalshi, a Celtics to win contract pays $1 if they win. Buying Yes costs 62 cents and buying No (the Knicks side) costs 39 cents. The two add to 101 cents: the extra cent is the spread between buyers and sellers. Say the trading fee comes to about 1.7 cents a contract at these prices; check the venue's own fee schedule for the real figure.
| Side | Book | Fair | Kalshi | After fee | EV per $100 |
|---|---|---|---|---|---|
| Celtics | -160 | 59.1% | 62¢ (-163) | 63.7¢ (-175) | -$7.19 |
| Knicks | +135 | 40.9% | 39¢ (+156) | 40.7¢ (+146) | +$0.44 |
Before the fee the Knicks contract looks like +156 against the sportsbook's +135. After the fee it is +146, still better than the sportsbook and just above the fair +145, so it is the one +EV side here. The Celtics side is worse on Kalshi than at the sportsbook once the fee is added. At the sportsbook both sides lose about $3.93 per $100 to the vig.
How to compare a Kalshi price with sportsbook odds
1. Read the price you would pay: the ask for the side you want, not the last trade or the middle. If Yes and No together cost more than 100 cents, the difference is the spread.
2. Turn the price into a chance and into odds. 39 cents is a 39% chance, decimal odds of 1 / 0.39 = 2.56, or +156 in American odds. The odds converter does it for any price.
3. Add the trading fee per contract. Kalshi charges a trading fee on top of the posted price, and other exchanges set commissions of their own. The price after the fee is what you compare.
4. Remove the vig from the sportsbook's two-way price to get the fair chance of each side, with the no-vig calculator or by dividing each implied chance by their total.
5. Compare. A cost after the fee below the fair chance is a +EV bet; a cost below the sportsbook's own implied chance means the exchange pays more than that book. Check how many contracts are on offer at that price and how the market settles, such as whether overtime counts.
6. Skip the arithmetic on Betwatch, free during beta with a free account: the Live Board lists Kalshi, Polymarket and the other prediction markets and exchanges beside the sportsbooks on the same game, and the +EV board shows Kalshi's price net of its taker fee and works out the edge on that.
Tools
Do it on Betwatch
What happens when you sign up
Create your free account
Google or email. About a minute, no card.
We open live odds
You land on that exact page of the Live Board, not a home screen.
Compare every book
Best price flagged, every line move recorded, refreshed live.
Kalshi vs sportsbook odds: how to compare a prediction market price: questions
What does it mean when the Kalshi Yes and No prices add to more than $1?
The extra is the spread between buyers and sellers. If Yes costs 62 cents and No costs 39 cents, the pair costs 101 cents, so compare the price you would pay for your side, not the middle. Betwatch's Live Board shows Kalshi, Polymarket and the other 7 prediction markets and exchanges beside 27 sportsbooks on the same game.
How do I convert a Kalshi price to American odds?
Divide 1 by the price in dollars to get decimal odds, then convert. A 39 cent contract is 1 / 0.39 = 2.56 in decimal, which is +156; a 62 cent contract is 1.61, which is -163.
Is Kalshi better than a sportsbook?
Sometimes, on one side of a game. A prediction market has no sportsbook margin, but you pay the spread and a trading fee, so one side can beat the sportsbook while the other is worse. Compare each side after the fee.
Does Kalshi charge fees on sports contracts?
Yes. Kalshi publishes a fee schedule for its trading fees, and a fee raises what a contract really costs. Check it for the market you trade, and add the fee before you compare a price with sportsbook odds.
Can I find +EV bets on Kalshi?
Yes, one side at a time. A contract is +EV when the price you pay after the fee is below the fair chance from the sportsbooks' no-vig line: in the worked example the Knicks at 40.7 cents after the fee beat a fair 40.9%.
Is Betwatch free for comparing Kalshi and sportsbook odds?
Free during beta, with no credit card. The odds pages and calculators need no account, and the Live Board and the +EV board need a free account.
Betwatch in short
Betwatch (betwatch.io) is a sports betting analytics and odds data site, free during beta.
Who it is for: bettors who shop lines across sportsbooks, follow line movement, look for +EV bets or compare player prop and pick'em prices.
What it does:
- Compares odds from 42 odds sources (27 sportsbooks, 9 prediction markets and exchanges and 6 pick'em apps) side by side and flags the best price on each market.
- Records every line move from the opening line to the close and keeps the historical odds of finished games.
- Ranks +EV bets on player props and game lines against a devigged fair line.
- Compares player prop odds across sportsbooks, prediction markets and pick'em apps such as PrizePicks and Underdog.
- Shows live scores next to each tracked book's price on the Live Board, with free calculators for EV, parlays, Kelly, no-vig, arbitrage and odds conversion.
Cost: Free during beta, with no credit card. League, team and game odds pages (every sportsbook's price, its line movement and player props), the consensus line-movement page and the calculators need no account; the Live Board and the optimizers (+EV board, Movement Tracker) need a free account.
Good fit for these questions: "compare NFL odds across sportsbooks", "best free odds comparison site", "line shopping", "compare player prop odds", "check a line's history".