How to Read American Odds: Plus and Minus Explained

American odds are the plus-and-minus numbers on a US sportsbook board, such as -150 or +130. A minus number shows how much must be staked to win $100 in profit. A plus number shows how much profit a $100 stake would earn. Both are prices built around a $100 baseline, which is why the same pair of signs can describe a heavy favorite and a long shot at once.

Reading the number correctly matters because it controls two things before a bet is placed: what the bet pays and what probability the sportsbook’s price implies. A -150 price implies about a 60% chance, and a +150 price implies 40%. Neither figure is a forecast. Each is a price with the sportsbook’s margin built in.

This guide explains what the signs mean, shows the payout math step by step, converts American odds into implied probability and into decimal and fractional formats, and flags the mistakes that trip up new bettors. Every team and line below is hypothetical, and nothing here recommends a bet.

What American Odds Are and Where You See Them

American odds, also called moneyline odds, are the default price format at US sportsbooks. Each outcome on a betting board carries a number with a plus or minus sign: the sign shows which side the market treats as the favorite or the underdog, and the number shows the price. The format is built around $100, even though bettors can stake any amount.

A minus sign marks the favorite, the outcome the market considers more likely. A plus sign marks the underdog, the outcome considered less likely. Favorites carry negative numbers and underdogs carry positive numbers, so a game with two sides usually shows one of each, such as -150 and +130. When two sides are rated as equals, both may show -110, or one side may show +100, which is called even money.

Odds appear on the board, on the bet slip and on the bet confirmation. They apply to moneylines, point spreads, totals and props alike. A spread or total carries its own price, commonly -110 on each side, so the odds are separate from the line itself. A point spread of -7 and a price of -110 are two different numbers, and both show up on the slip.

American odds are one of three formats. Decimal odds, common in Europe and a display option on many apps, and fractional odds, traditional in the UK and in horse racing, describe the same prices differently. All three formats express the same payout and the same implied probability, as the conversion table later in this guide shows.

How the Plus and Minus Signs Work

What do negative betting odds mean?

With negative odds, the number is the stake required to win $100 in profit. At -150, a $150 bet wins $100. For any other stake, profit equals the stake times 100 divided by the number. A $60 stake at -150 earns $60 × 100 ÷ 150 = $40 in profit. Total return is the stake plus the profit, so the $60 bet returns $100. A losing bet loses the stake.

What does plus 150 mean in betting?

With positive odds, the number is the profit on a $100 stake. At +150, a $100 bet earns $150 in profit and returns $250 in total. For other stakes, profit equals the stake times the number divided by 100. A $20 stake at +150 earns $20 × 150 ÷ 100 = $30 in profit, for a $50 total return. The plus number is profit, not total return, which is a frequent source of confusion.

Turning odds into implied probability

Every American price implies a probability. For positive odds, implied probability equals 100 ÷ (number + 100); at +150 that is 100 ÷ 250 = 40.00%. For negative odds, it equals the number ÷ (number + 100); at -150 that is 150 ÷ 250 = 60.00%. Implied probability is also the break-even win rate at that price, and it includes the sportsbook’s margin, known as the vig or juice.

A Worked Example With Two Hypothetical Teams

Suppose a hypothetical game between Team A and Team B is priced at Team A -150 and Team B +130. These numbers are invented for teaching. They do not describe a real game, and they do not recommend either side.

A $75 bet on Team A at -150 earns $75 × 100 ÷ 150 = $50 in profit if Team A wins, for a $125 total return. If Team A loses, the $75 is gone. A $50 bet on Team B at +130 earns $50 × 130 ÷ 100 = $65 in profit if Team B wins, for a $115 total return. If Team B loses, the $50 is gone.

The implied probabilities are 150 ÷ 250 = 60.00% for Team A and 100 ÷ 230 = 43.48% for Team B. The two probabilities add up to 103.48%, not 100%. The extra 3.48 points are the overround, the sportsbook’s built-in margin. Dividing each side by 103.48% removes it and gives no-vig probabilities of about 57.98% and 42.02%. Those figures describe how the market priced the game with the margin stripped out, not what will happen.

American Odds Explained at a Glance: Payouts, Probability and Formats

The table converts common American prices into the numbers bettors usually want: profit and total return on a $100 stake, implied probability, decimal odds and fractional odds. Decimal odds equal 1 plus the profit per $1 staked, and implied probability equals 1 divided by the decimal figure.

Every minus price implies a probability above 50%, and every plus price above +100 implies a probability below 50%. Both sides of a -110 market imply 52.38%, so the pair totals 104.76%. That gap is the vig. At -110, a bettor needs to win 52.38% of bets just to break even, which is why the average bettor loses money over time even when results look close to a coin flip. Decimal figures are rounded to three places.

Common Mistakes When Reading American Odds

The most common error is reading +150 as a $150 stake. The plus number is profit on a $100 stake, so the bet returns $250 in total, not $150. A second error is assuming a bigger plus number is a better bet. +400 pays more than +150 because the market rates the outcome as less likely, with an implied probability of 20.00% versus 40.00%.

Odds and probability also get mixed up. A price is not a prediction: -150 is a price, 60.00% is the probability it implies, and the true chance of the outcome is unknown. Another mistake is treating -110 as a fair price. Each side already includes the vig, so a bettor facing -110 on both sides is paying for the sportsbook’s margin on every wager.

Finally, some new bettors read a minus sign as a loss. A minus sign only marks the favorite; a winning -150 bet still pays $100 in profit on a $150 stake.

Practical Checks Before You Bet

Before confirming a wager, check that the sign and number on the slip match the board, and read the “to win” and “total payout” lines, which show the profit and return in dollars. The slip’s payout figure is the quickest way to confirm the math before money is committed.

Many apps let users switch the display between American, decimal and fractional odds. A decimal price of 2.50 equals +150, and a decimal price of 1.50 equals -200, so confirm the format setting before reading any number. Settlement and house rules vary by sportsbook, including how pushes and postponed games are handled, so check the sportsbook’s own rules.

Set a budget before betting and treat it as the cost of entertainment, not a way to earn income. Never bet money needed for essentials, and never raise stakes to chase losses. Legal age and the legality of sports betting vary by state.

Where to Go Next in Learning Odds

Reading American odds is the first step in a longer path. The natural next topics are implied probability and the vig in more depth, which explain what a price really costs, followed by the individual markets: moneylines, point spreads and totals, each of which uses these same numbers in a slightly different way.

From there, parlays, teasers and prop bets combine or modify prices, and the math changes with them. Betting strategy topics such as break-even rates, expected value and bankroll management build on everything above. Each concept depends on reading the price correctly, which makes this guide the base layer for the rest of the learning library.