Every sportsbook in the US displays odds in American format — the numbers with plus and minus signs that look intimidating until you understand them. Once you do, you'll read a betting board the way you read a menu. It takes about five minutes to learn.
The basics: plus and minus
Minus (-) odds tell you how much you need to risk to win $100. If the odds are -150, you must risk $150 to win $100 in profit (and get your $150 back, for a total return of $250).
Plus (+) odds tell you how much you win on a $100 bet. If the odds are +130, a $100 bet wins you $130 in profit (plus your $100 back, for a total return of $230).
Negative odds = favorites (more likely to win, lower payout). Positive odds = underdogs (less likely to win, higher payout).
-200: Risk $200 to win $100. Total return: $300.
-110: Risk $110 to win $100. Total return: $210.
+100: Risk $100 to win $100. Even money.
+150: Risk $100 to win $150. Total return: $250.
+300: Risk $100 to win $300. Total return: $400.
Calculating payouts for any dollar amount
You don't have to bet exactly $100. You can bet any amount. Here's how to calculate your payout:
You bet $25 at -110 odds.
Profit = $25 × (100 ÷ 110) = $25 × 0.909 = $22.73
Total return if you win: $25 + $22.73 = $47.73
You bet $25 at +175 odds.
Profit = $25 × (175 ÷ 100) = $25 × 1.75 = $43.75
Total return if you win: $25 + $43.75 = $68.75
Why -110 is everywhere
Look at any point spread or total on any sportsbook, and you'll see -110 on both sides. This is the standard vig (vigorish) — the sportsbook's built-in commission.
Here's why -110 matters: at -110 odds, you need to win 52.4% of your bets just to break even. Not 50%. That extra 2.4% is the sportsbook's profit margin. It's the tax you pay on every bet.
This means that when you're betting spreads and totals at standard -110 odds, you need to be right more than 52.4% of the time to make money. That's the threshold. Everything in your +EV strategy is about consistently clearing it.
Odds tell you the implied probability
Every set of odds implies a probability. Knowing how to convert between the two is essential for identifying +EV bets. We cover this in detail in Implied Probability: The Hidden Number Behind Every Bet.
The quick version:
The mental shortcut
For negative odds close to -110 (the most common), a quick shortcut: divide 100 by the odds number (ignoring the minus sign) and you get the approximate profit per dollar. At -110, that's 100 ÷ 110 = $0.91 per $1 risked. At -150, it's 100 ÷ 150 = $0.67 per $1 risked. At -200, it's $0.50.
For positive odds: the number itself is the profit per $100. +150 = $150 profit on a $100 bet. Simple.
If you want to convert between American, decimal, and fractional odds instantly, use the odds converter on our homepage.
The bottom line: Minus odds show what you risk to win $100. Plus odds show what you win on a $100 bet. The standard -110/-110 line means you need to win 52.4% of your bets to break even — and everything in the +EV system is about beating that number.
Run the numbers before you bet.
The BeginnerBets +EV Calculator shows you instantly whether a bet is worth placing — based on math, not gut feeling.
Open +EV Calculator →