How betting odds work: what they are and how to use them

A variation of fractional odds is known as Hong Kong odds. However, not all fractional odds are traditionally read using the lowest common denominator (i.e. simplifying the fraction when possible). In either case, having won, the bettor always receives the original stake back too; so if the odds are 4/1 the bettor receives a total of £500 (£400 plus the original £100). Favoured by bookmakers in the United Kingdom and Ireland, and also common in horse racing, fractional odds quote the net profit that will be paid out to the bettor, should they win, relative to the stake.

“Vegas odds” traditionally referred to the betting lines set by Las Vegas sportsbooks, which were once the hub of sports betting in the U.S. When sharp bettors place heavy wagers, sportsbooks take this as a signal that these bettors have valuable information or insights. For example, if the majority of bettors back a popular team, the sportsbook may adjust the line to make the less popular team more attractive. This format keeps games thrilling until the final whistle, adding intensity even to potential blowouts. Bets in sports betting come in various forms, generally focused on picking winners, predicting score margins, or anticipating total points.

In most cases, the favorite will have negative moneyline odds (less payoff for a safer bet) and the underdog will have positive moneyline odds (more payoff for a risky bet). A “moneyline” wager refers to odds on the straight-up outcome of a game with no consideration to a point spread. For example, 6/5 fractional odds (also described as “1.2” or “6 to 5”) are the same as 11/5 decimal odds (also described as 2.2 or “11 for 5).

For decades, Vegas was seen as the gold standard for odds-setting, with casinos along the Strip acting as trendsetters for the broader betting market. Sharp action – bets placed by professional or experienced bettors – also triggers line movement. When a large number of casual bettors, often called “public” bettors, place money on one side, the line may shift to reflect this surge in interest. By shifting the line, they encourage bettors to wager on the opposite side, helping maintain even exposure on both outcomes. They range from player stats, like total points scored by a star player, to quirky events like the length of the national anthem. Prop bets, short for proposition bets, focus on specific events or outcomes within a game, rather than the final score.

You may also see odds expressed with the lowest number first e.g. 1/2 or 2/7. Once you understand betting odds and the differences between them, reading them becomes easy. Fractions were traditionally used to bet on horse racing and were most popular in high street betting shops in the UK, before the advent of internet gambling. Betting odds are usually expressed either as fractions (e.g. ‘3/1’) or as decimals (e.g. 4.0).

The value bets page compares the odds of each bookmaker with the average odds for the same outcome, highlighting the markets where one price stands out, with the probability included. OddsPortal has a number of betting tools that can bring your attention to interesting markets you may never have thought about betting on before, always with the best available price. The same price is 3/1 in fractional odds and +300 in American odds, which means a 100 bet wins 300 on top of the stake.

Since these bets can be made months in advance, they offer a chance for big payouts, especially when backing underdogs. Instead of betting on a single game, you’re predicting outcomes like who will win the NBA championship, MVP award, or a division title. Bettors predict whether the total points scored will be above or below a set number. For example, if a team is -5.5, they need to win by 6 or more points to win the bet.

Instead of just picking a winner, you’re betting on whether a team can “cover the spread,” meaning they either win by a certain margin or avoid losing by too much. If you see +250, that team is the underdog; a $100 bet would return $250 if they win. Moneyline bets are the simplest form of sports betting, focusing solely on picking a winner. Some bets involve combining multiple outcomes for higher rewards, while others target specific in-game events or achievements.

If you are new to sports betting or have been betting for years, the betting odds today shown for each match tell you where every price is best, so a winning bet always pays out as much as it can. Open our American football odds page for the next games, with past results and the prices they closed at. We cover the NHL, the SHL in Sweden and the KHL among many hockey leagues, with prices on single games and on the outright winners. Basketball goes from NBA odds and the EuroLeague to domestic leagues such as the Super Lig in Turkey and the LNB in France, with prices on single new betting sites games and on the outright winners. Before a bet, check the archived results and historical odds of the teams or players involved, across leagues and tournaments worldwide.