Also called moneyline odds — the standard format across US sportsbooks for NFL, NBA, MLB, and NHL betting.
American odds are based on a $100 stake reference point. The sign tells you whether you're betting on the favourite or the underdog:
The underdog. Shows profit on a $100 bet. +150 means bet $100 to win $150 profit ($250 total return).
The favourite. Shows stake needed to win $100. -200 means bet $200 to win $100 profit ($300 total return).
| American | Conversion | Decimal | Implied % |
|---|---|---|---|
| +150 | (150÷100)+1 | 2.50 | 40% |
| +300 | (300÷100)+1 | 4.00 | 25% |
| -110 | (100÷110)+1 | 1.91 | 52.4% |
| -200 | (100÷200)+1 | 1.50 | 66.7% |
You'll see -110 constantly in US sports betting — it's the standard "juice" or vig on point spread and total bets. It implies a 52.4% probability requirement just to break even, which is the bookmaker's built-in margin on most spread markets.
It's a historical convention from American sportsbooks and casinos, making it easy to quickly assess return on a "standard" bet size without a calculator.
Yes — both represent even money (50% implied probability), equivalent to decimal 2.00 or fractional 1/1. They're functionally identical at that point.
Enter any +/− American odds and see all seven format equivalents plus implied probability and payout on your stake.