Everything on a sportsbook — every line, every price, every payout — is built on odds. Understand these three formats and the idea of implied probability, and you can read any betting board on earth.
The same bet can be written three ways, depending on where you are in the world:
They're just three languages for the same thing. A −110 American line is exactly the same bet as 1.91 decimal or 10/11 fractional. Try converting between them with our odds converter.
American odds are always quoted relative to $100:
You don't have to bet $100 — the odds scale to any stake. A $55 bet at −110 wins $50. A $20 bet at +150 wins $30.
Every price implies a probability: how likely the outcome must be for the bet to "break even" before the bookmaker's margin. This is the single most important idea in betting.
Here's the catch: add up the implied probabilities of both sides of a market and you'll get more than 100% — usually 104–106%. That extra is the vig (juice), the bookmaker's cut. Our vig remover strips it out to show the true no-vig probabilities.
A standard board line for one game shows three markets side by side:
| Team | Spread | Total | Moneyline |
|---|---|---|---|
| Chiefs | −3 (−110) | O 47.5 (−110) | −150 |
| Raiders | +3 (−110) | U 47.5 (−110) | +130 |
Each of these is covered in depth — with worked examples — in Bet types.
Two numbers matter: profit (what you win) and total return (profit + your original stake back). The easiest mental math uses decimal odds:
For American odds: at −110, divide your stake by 1.10 to get profit ($110 ÷ 1.10 = $100). At +150, multiply your stake by 1.50 ($100 × 1.50 = $150 profit). Or skip the math and use the payout calculator.
Next: Bet types → — moneyline, spread, totals, parlays, teasers, props, futures and live betting, each with a worked example.