American Odds: What They Mean in Betting
American odds, also called moneyline odds, are the standard format used by sportsbooks in the United States. They use a plus (+) or minus (-) sign followed by a number. While British bettors primarily encounter fractional or decimal odds, American odds appear increasingly on international platforms, in US-focused football coverage, and on betting exchanges that serve a global audience.
Understanding this format is useful for comparing prices across international markets, particularly for major tournaments and Champions League fixtures covered by US sportsbooks.
How Plus Odds Work
A plus sign indicates the underdog or a selection at odds-against. The number shows how much profit you make on a 100 unit stake.
+250 means a 100 pound stake returns 250 pounds profit, plus your 100 pound stake back, for a total of 350 pounds.
Some football examples:
- Brentford to beat Arsenal at +320: a 10 pound stake profits 32 pounds (total return 42 pounds)
- Draw in Liverpool vs Chelsea at +240: a 10 pound stake profits 24 pounds (total return 34 pounds)
- Wolves to beat Manchester City at +500: a 10 pound stake profits 50 pounds (total return 60 pounds)
The formula for plus odds is:
Profit = Stake x (American Odds / 100)
How Minus Odds Work
A minus sign indicates the favourite. The number shows how much you need to stake to win 100 units of profit.
-200 means you need to stake 200 pounds to win 100 pounds profit. Your total return would be 300 pounds.
Some football examples:
- Manchester City to beat Bournemouth at -250: a 10 pound stake profits 4 pounds (total return 14 pounds)
- Arsenal to beat Nottingham Forest at -180: a 10 pound stake profits 5.56 pounds (total return 15.56 pounds)
The formula for minus odds is:
Profit = Stake / (American Odds / 100)
Note that you divide by the absolute value of the minus number.
Converting American Odds
To Decimal Odds
For plus odds: (American Odds / 100) + 1
- +250 becomes (250 / 100) + 1 = 3.50
For minus odds: (100 / American Odds) + 1
- -200 becomes (100 / 200) + 1 = 1.50
To Fractional Odds
For plus odds: Express the number over 100 and simplify.
- +250 becomes 250/100, simplified to 5/2
For minus odds: Express 100 over the number and simplify.
- -200 becomes 100/200, simplified to 1/2
To Implied Probability
For plus odds: 100 / (American Odds + 100) x 100
- +250: 100 / 350 x 100 = 28.6%
For minus odds: American Odds / (American Odds + 100) x 100
- -200: 200 / 300 x 100 = 66.7%
Quick Reference Table
| American | Decimal | Fractional | Implied Probability |
|---|---|---|---|
| -400 | 1.25 | 1/4 | 80.0% |
| -200 | 1.50 | 1/2 | 66.7% |
| -110 | 1.91 | 10/11 | 52.4% |
| +100 | 2.00 | Evens | 50.0% |
| +150 | 2.50 | 3/2 | 40.0% |
| +250 | 3.50 | 5/2 | 28.6% |
| +500 | 6.00 | 5/1 | 16.7% |
Why US Bettors Use This Format
American odds evolved from the culture of US sports betting, where the focus is on a "100 dollar" unit. The format makes it immediately clear whether a selection is favoured (minus) or an underdog (plus), and the numbers directly tell bettors how much they win or need to risk in relation to 100 dollars.
For UK football bettors, the main reason to understand American odds is to compare lines across international sportsbooks. Some US-based platforms offer competitive prices on Premier League and Champions League markets. Past performance does not guarantee future results, but comparing odds across formats is a useful analytical habit.
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