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

Once you’re familiar with the basic math, fractional odds become an easy way to see potential profits relative to the stake. They’re especially popular in horse racing, where bettors often look for value in underdog picks or assess returns more precisely using this format. Fractional odds can be a bit trickier to calculate quickly, but they’re favored by many bettors for how clearly they represent the risk-reward ratio. If you bet $10 at 7/2, you’d get $35 in profit plus your initial $10 back, totaling $45. They’re expressed as fractions, like 5/1 or 7/2, showing the ratio of profit to the original stake. Decimal odds make comparing bets straightforward because you’re seeing the total return value in one number.

In betting terms, probability is odds expressed as a percentage. Moneyline odds use $100 as the evens line, with either positive or negative outcomes. If you’d like a bit more guidance, we have a full guide on how fractional odds work in betting. You may also see odds expressed with the lowest number first e.g. 1/2 or 2/7.

These bets can cover anything from team milestones to individual performances, making games more interactive and fun. Futures keep you invested throughout the season, adding suspense as teams rise or fall and turning each game into a step toward your bigger prediction. For instance, if the line is 220.5 in an NBA game, you’d bet on whether the teams’ combined score will be over 220 or under 220.5. Totals bets, also known as Over/Under bets, focus on the combined score of both teams rather than who wins.

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. This is a difficult task considering the huge teams of mathematicians that they employ. Moneyline, or American, odds are favoured by US bookmakers and punters, and are often expressed as positive and negative values (e.g. +250, -400). Bet £10+ on any sportsbook markets at odds of evens (2.00) or greater. “Double the odds” applies to fractional odds profits only, with extra winnings paid in cash on settlement.

Multiplying these probabilities by 100% gives the percentage. When probability is expressed as a number between 0 and 1, the relationships between probability p and odds are as follows. When Moneyline odds are quoted as a positive number +X, it means that a wager pays X to 100. However in many situations, the possible loss (“stake” or “wager”) is paid up front and, if the gambler wins, the net win plus the stake is returned. From local leagues to international tournaments, our website shows the top price for every outcome before you bet.

The dropping odds page shows when the odds on a team, player or market have dropped before the start of a match. Whichever region you are playing from, there are multiple betting sites, or sportsbooks as they are called in the US, offering odds for each event and market on our site. From the top divisions to smaller leagues and events, you can spot the best bet odds today across all the games of the day.

OddsPortal is a free odds comparison site where you can compare betting odds from leading bookmakers on every match. Odds comparison, also known as line shopping, means checking the price betting sites not covered by gamstop of the same outcome at several bookmakers and taking the highest one. With results, standings, predictions and the best odds on the same site, you can check the top price before every bet. We also compare prices on boxing and MMA, where big fights are added as soon as bookmakers publish odds, on esports and on rugby union, rugby league, baseball, volleyball, Aussie rules and many more.

Free bet valid 7 days from issue, usable on any Sport/Market as a 3+ fold ACCA with total odds 3.00–21.00, each leg 1.50+. Bonus funds are separate to cash funds and subject to 10x wagering requirement (bonus funds). #AD 18+ New players only.