How to Read NBA Odds: Moneyline, Spread and Totals Explained (Plus American vs. Decimal Odds)

Short answer: NBA odds come in three main markets. The moneyline is who wins, the spread is the winning margin against a handicap, and the total is the combined score over or under a line. In the U.S. the prices are written as American odds like -150 or +130; in Norway and the rest of Europe the same prices are decimals like 1.67 or 2.30. A minus number tells you what you risk to win $100, a plus number what $100 wins, and a decimal tells you the full return per unit, stake included. The conversion table below covers the numbers you will actually see.

Every Celtics game comes with a little line of numbers on the broadcast: Celtics -6.5, o/u 224.5, BOS -260. If you have nodded along without being sure what they mean, you are in good company. And if you have a friend in Oslo or Stockholm who talks about the same game in "1.38" and "2.95", they are describing the exact same prices in a different language. Here is the translation, market by market.

American vs. decimal odds: two ways to write one price

Odds formats are regional habits. The U.S. uses moneyline numbers with a plus or a minus, the UK grew up on fractions like 5/2, and continental Europe, including Norway, settled on decimals. Wikipedia's article on fixed-odds betting puts it plainly:

"decimal odds are favored in Continental Europe, Australia, New Zealand, and Canada. Moneyline odds are used in the United States." – Source: Wikipedia, "Fixed-odds betting"

The rules for American odds are simple once you see them side by side:

• Minus number (favorite): how much you risk to win $100. At -150 you risk $150 to win $100.

• Plus number (underdog): how much a $100 bet wins. At +130 a $100 bet wins $130.

• Decimal odds: the total return per 1 unit staked, stake included. At 2.30, a 100 bet returns 230, which is 130 profit plus the 100 you put in.

Converting is just as quick. For a plus number, divide by 100 and add 1: +130 becomes 2.30. For a minus number, divide 100 by the number and add 1: -150 becomes 1.67. The Norwegian guide to decimal, fractional and American odds formats runs through the same math with kroner and adds the Asian formats you sometimes see on international sites, if you want the full picture.

Conversion table: American, decimal and implied probability

Implied probability is the chance of winning that a price represents, before you account for the bookmaker's margin. In decimal odds it is simply 1 divided by the odds.

Notice the -110 row. That is the standard price on both sides of most NBA spreads and totals. Two sides at 52.4% add up to about 104.8%, and the extra 4.8% is the bookmaker's built-in margin, often called the vig or juice. In Europe the same line shows up as roughly 1.91 on each side.

The moneyline: just pick the winner

The moneyline is the simplest NBA bet. You pick the team that wins the game, overtime included. Because basketball has no draws, there are only two outcomes. Say Boston hosts a rebuilding team and the line reads Celtics -260, opponent +210. In decimal terms that is about 1.38 and 3.10. A $100 bet on Boston returns $138.46 in total if they win; $100 on the underdog returns $310.

The catch with the moneyline in the NBA is that heavy favorites pay very little. That is exactly why the spread exists.

The spread: a handicap in points

The spread levels the field by giving the underdog a head start on the scoreboard. If the Celtics are -6.5, they have to win by 7 or more for a bet on them to win. The opponent at +6.5 covers if they win outright or lose by 6 or fewer. Wikipedia sums up the idea in one line:

"The point spread is essentially a handicap towards the underdog." – Source: Wikipedia, "Spread betting"

Half-point lines like 6.5 always produce a winner. Whole numbers do not. If the spread is -6 and Boston wins by exactly 6, the bet is a push and you get your stake back. Europeans know this logic from football, where it is called Asian handicap: half lines are settled one way or the other, whole lines refund the stake when the result lands exactly on the number. This Norwegian walkthrough of how Asian handicap lines like 0, 1.0 and 1.5 are settled explains the same push-and-refund rule with goals instead of points, and it maps one-to-one onto NBA spreads.

Totals: over or under the combined score

The total ignores who wins. The bookmaker sets a line for the combined points of both teams, say 224.5, and you decide whether the final score lands over or under it. A 115–112 game adds up to 227, so the over wins. A 108–110 grinder adds up to 218, and the under wins. Pace, three-point volume, rest days and who is sitting out all push the number around. In Norway this market is called over/under too, and the guide to how over/under lines and their margin work shows how a half line always has a winner and how to calculate the margin from the two prices.

Other NBA markets you will see

• Quarter and half lines: spread, total and moneyline for just the first half or a single quarter.

• Team totals: over/under on one team's points only.

• Player props: points, rebounds, assists or threes for a single player, usually as an over/under line.

• Futures: season-long bets on the champion, conference winners or awards such as MVP.

• Live lines: spreads and totals that update during the game as the score and the clock change.

Why the Celtics are so often the favorite

Boston fans get used to seeing a minus sign next to their team. History is part of it:

"The Celtics are commonly regarded as the most successful team in NBA history." – Source: Wikipedia, "Boston Celtics"

Lines are not built on banners, though. They are built on current strength, injuries, rest and where the money goes. That is why a Celtics team missing two starters on the second night of a back-to-back can be a small favorite or even an underdog against a team it would normally handle. Media day talk, like Jayson Tatum's 2026 Media Day presser, is the first hint of how a roster will look before the market settles. If you want a reminder of how much a lineup matters, our 1980s Celtics all-decade team is a good case study in what a full-strength roster looked like.

Quick checklist for reading an NBA line

• Find the minus sign. That is the favorite, on both the moneyline and the spread.

• Check if the spread is a half point or a whole number. Whole numbers can push.

• Look at the price next to the spread or total. -110 (1.91) is standard; anything else tells you the line is leaning.

• Convert to decimal if you think in European terms: plus numbers divide by 100 and add 1, minus numbers divide 100 by the number and add 1.

• Turn the price into a percentage with 1 divided by the decimal odds, and ask whether you really think the chance is higher than that.

• Read the injury report last thing before tip-off. NBA lines move most on late lineup news.

FAQ

What does -110 mean in NBA betting?

You risk $110 to win $100. In decimal odds that is about 1.91, an implied probability of 52.4%. It is the standard price on most NBA spreads and totals.

How do I convert American odds to decimal odds?

For plus odds, divide by 100 and add 1 (+150 becomes 2.50). For minus odds, divide 100 by the number and add 1 (-200 becomes 1.50).

What happens if the final margin equals the spread?

If the spread is a whole number, like -6, and the team wins by exactly 6, the bet is a push and the stake is returned. Half-point spreads like -6.5 cannot push.

Does overtime count in NBA bets?

For full-game moneylines, spreads and totals, yes. Overtime points count toward the final result. Quarter and half bets only count their own period.

Why do Europeans use decimal odds?

It is a regional convention. Decimal odds show the total return per unit staked, which makes it easy to compare prices and calculate payouts at a glance.