American Odds Explained: How to Read Plus and Minus Betting Lines
Learn how American odds work, what plus and minus prices mean, and how to convert betting lines into implied probability and potential payouts.
American odds are a betting format used to show either the potential profit on an underdog or the amount required to win a set profit on a favorite. They are also called moneyline odds and are usually displayed with a plus or minus sign, such as +150 or -200.
The quickest way to read them is simple: a positive number shows how much profit a $100 stake could earn, while a negative number shows how much must be risked to make $100 profit. The original stake is returned separately when the bet wins.
What plus and minus American odds mean
Positive odds: the underdog
Positive American odds normally identify the less likely outcome. At +150, a $100 stake would produce $150 in profit. The total payout would be $250: $150 profit plus the returned $100 stake.
The same price can be adjusted for a different stake. A $20 bet at +150 would generate $30 in profit, making the total payout $50. The calculation is:
Profit = stake × odds ÷ 100
Positive odds do not guarantee that an outcome is unlikely in every market. They simply indicate that the sportsbook has priced it as the less expensive side to back relative to the favorite.
Negative odds: the favorite
Negative American odds normally identify the favorite. At -200, a bettor must risk $200 to make $100 in profit. A $20 stake at the same odds would earn $10 in profit, producing a $30 total payout.
For negative prices, the profit calculation is:
Profit = stake × 100 ÷ absolute odds
“Absolute odds” means removing the minus sign before calculating. For example, the absolute value of -125 is 125.
How to calculate American odds payouts
To find the total return, add the original stake to the potential profit. This distinction matters because betting sites may display either “potential profit” or “total payout.” They are not the same figure.
- +125 with a $40 stake: $50 profit and a $90 total payout.
- -125 with a $40 stake: $32 profit and a $72 total payout.
- +300 with a $25 stake: $75 profit and a $100 total payout.
- -300 with a $25 stake: about $8.33 profit and a total payout of about $33.33.
For a quick estimate, a positive line such as +250 returns two and a half times the stake as profit. A negative line such as -250 returns 40 cents of profit for every dollar risked.
American odds and implied probability
Implied probability is the chance suggested by the betting price before accounting for the sportsbook’s margin, often called the vig or overround. It is not a prediction that the outcome will happen.
For positive odds, use:
Implied probability = 100 ÷ (odds + 100) × 100
For negative odds, use:
Implied probability = absolute odds ÷ (absolute odds + 100) × 100
Examples:
- +150: 100 ÷ 250 = 40% implied probability.
- -200: 200 ÷ 300 = 66.67% implied probability.
- +300: 100 ÷ 400 = 25% implied probability.
In a two-outcome market, adding the implied probabilities will usually produce more than 100%. That excess represents the bookmaker’s built-in margin. Comparing prices across licensed sportsbooks can reduce the effect of that margin, but it cannot remove betting risk.
American odds compared with decimal and fractional odds
Different regions use different odds formats. American odds are common in the United States and Canada, while decimal odds are widely used internationally and fractional odds remain familiar in the United Kingdom and Ireland.
| American | Decimal | Fractional | Implied probability |
|---|---|---|---|
| +150 | 2.50 | 3/2 | 40% |
| -200 | 1.50 | 1/2 | 66.67% |
| +300 | 4.00 | 3/1 | 25% |
To convert American odds to decimal odds, add 1 to the profit multiplier. +150 becomes 2.50, while -200 becomes 1.50. Decimal odds represent the total return for each unit staked, including the original stake.
American odds in sports betting markets
American odds can appear on moneyline bets, point spreads, totals, futures, player props, and parlay selections. The plus-or-minus meaning stays the same even though the market changes.
A moneyline price applies to the selected team or player winning. A spread price applies after a handicap is added, and a totals price applies to whether the combined score goes over or under a posted number. A favorite may have -110 odds on a spread or total even when the underlying matchup is relatively close.
Parlays combine multiple selections. The displayed American price reflects the combined probability and sportsbook margin, so a larger potential payout also comes with a lower chance that every selection wins. Each leg must generally win for the parlay to pay.
Common mistakes when reading betting odds
- Confusing profit with payout: the stake is usually included in the total return but not in the listed profit.
- Assuming a favorite is a safe bet: negative odds indicate price, not certainty.
- Ignoring the stake size: the same line can produce very different results depending on the amount risked.
- Treating implied probability as a guarantee: it is a market-based estimate that includes the sportsbook’s pricing margin.
- Forgetting local rules: minimum stakes, taxes, settlement rules, and available markets vary by country and operator.
Use a calculator when odds include decimals or an unusual stake, and check whether a betting app labels its figure as profit or total return. Only bet with money you can afford to lose, follow the rules in your jurisdiction, and consider setting deposit or spending limits before placing wagers.
