American Odds Explained: Favorites, Underdogs and Payouts

What do those plus and minus numbers mean when you look at betting odds? If you’re new to US sports betting, American odds can seem confusing at first. This guide explains American odds in plain English, shows you how to read them, how to calculate payouts, and how to use the Kingpin odds converter to make sense of any price. You’ll also see common mistakes to avoid and tips for betting responsibly.

What Are American Odds? A Plain-English Definition

American odds are a way of displaying betting prices that show how much you can win or need to risk. They use either a plus (+) or minus (–) sign in front of a number. The sign and number tell you two things:

• Plus odds (+): Show how much profit you’d make on a $100 bet. These are usually for underdogs.
• Minus odds (–): Show how much you need to risk to try to win $100 profit. These are usually for favorites.

For example, +200 means you’d win $200 profit if you bet $100. –150 means you’d need to risk $150 to try to win $100 profit.

How Do American Odds Work? The Math Behind the Signs

Let’s break down the math for both types of American odds:

• Positive odds (+): The number is how much profit you’d make for every $100 you bet. For example, +150 means a $100 bet wins $150 profit (plus your $100 back).
• Negative odds (–): The number is how much you need to risk to try to win $100 profit. For example, –150 means you must risk $150 to try to win $100 profit (plus your $150 back if you win).

To convert American odds to decimal odds (another common format), use these formulas:

• For positive odds: Decimal = 1 + (odds / 100)
• For negative odds: Decimal = 1 + (100 / absolute value of odds)

Decimal odds show your total return per $1 bet, including your stake.

Worked Examples: Calculating Payouts and Implied Probability

Let’s see how this works with real numbers.

Example 1: Betting on an Underdog (+150)

• Odds: +150
• Stake: $100
• Profit: $100 × (150 / 100) = $150
• Total return: $100 (stake) + $150 (profit) = $250
• Decimal odds: 1 + (150 / 100) = 2.50

If you bet $100 at +150 and win, you get $250 back: $150 profit plus your $100 stake.

Example 2: Betting on a Favorite (–150)

• Odds: –150
• Stake: $150
• Profit: $150 × (100 / 150) = $100
• Total return: $150 (stake) + $100 (profit) = $250
• Decimal odds: 1 + (100 / 150) ≈ 1.67

If you bet $150 at –150 and win, you get $250 back: $100 profit plus your $150 stake.

Implied Probability

American odds can also be used to estimate the implied probability of an outcome. This is not a true probability, but a mathematical estimate based on the odds (which include the sportsbook’s margin).

• For positive odds: Implied probability = 100 / (odds + 100)
• For negative odds: Implied probability = absolute value of odds / (absolute value of odds + 100)

For example, +150 implies a probability of 100 / (150 + 100) = 0.40, or 40%. –150 implies a probability of 150 / (150 + 100) = 0.60, or 60%.

Common Mistakes and Limitations

• Confusing profit with total return: American odds show profit, not total payout. Always add your stake to find your total return.
• Assuming odds reflect true probability: Odds include the sportsbook’s margin (vig), so implied probability is not the actual chance of an outcome.
• Mixing up plus and minus: Remember, plus odds are for underdogs (higher payout for smaller risk), minus odds are for favorites (higher risk for smaller profit).
• Forgetting to check the stake: The formulas assume you’re betting $100, but you can scale up or down for any amount.
• Not accounting for vig: The odds are not a prediction or belief by the sportsbook—they are a price that includes margin.

Also, American odds are less intuitive for very small or very large numbers, and can be confusing when comparing to decimal or fractional odds used in other countries.

How to Use the Kingpin Odds Converter

The Kingpin odds converter helps you translate American odds into decimal or fractional odds, and see implied probability. Here’s how to use it:

1. Enter a valid American odds value such as -110 or +150.
2. Select Calculate to see the decimal odds, fractional odds, and implied probability.

This tool is especially helpful if you want to compare odds formats, check implied probability, or make sure you understand your potential payout. Remember, the calculator uses the standard formulas shown above, and results are based on the numbers you enter.

Limitations: The calculator does not account for promotions, free bets, or special rules. It also does not remove the sportsbook’s margin (vig) from the implied probability. Use it as a guide, not a guarantee.

Responsible Betting Tips

• Bet only what you can afford to lose. Treat betting as entertainment, not a way to make money.
• Understand the math before you bet. Make sure you know how much you’re risking and what you could win.
• Don’t chase losses. If you lose a bet, don’t increase your stakes to try to win it back.
• Take breaks and set limits. Use deposit or loss limits if your sportsbook offers them.
• Seek help if needed. If betting stops being fun or you feel out of control, reach out for support.

Summary

American odds use plus and minus signs to show how much you can win or need to risk. Plus odds (like +150) show profit on a $100 bet, while minus odds (like –150) show how much you must risk to try to win $100 profit. You can use simple formulas to convert American odds to decimal odds, calculate payouts, and estimate implied probability. The Kingpin odds converter makes these calculations easy—just enter your odds and select Calculate. Always remember to bet responsibly, understand the math, and never risk more than you can afford to lose.

Use the Kingpin calculator

Run your own numbers with the related Kingpin betting calculator. The tool applies the formulas described above and does not predict winners.

Bet responsibly

Sports betting involves risk. Never risk money you cannot afford to lose, never chase losses, and set firm time and spending limits. If gambling stops being fun, visit the National Council on Problem Gambling for help.