Updated: 12.05.2025
Sports betting can be a rocky terrain to navigate starting out, and when it comes to reading betting odds, you'll likely see them listed in a variety of ways. Don't be alarmed, though, because we're here to guide you through how to read those odds and how to calculate them so you know what you stand to win on any given bet.
The three main types of odds you'll see are American, fractional and decimal. Those are listed in accordance with how frequently you'll see them formatted in such ways at the major legal U.S. sportsbooks, many of whom we have partnerships with and can hook you up with big free bet deals upon creating an account.
But to stick with what's happening now, let's take a closer look at how to read betting odds.
This format of odds is most often displayed in triple-digit fashion, with either a positive or negative charge. If you glance at positive odds for a moneyline (e.g. +200), this indicates that team or athlete is an underdog. Thus, negative odds (e.g. -125) are suggestive of a favorite's moneyline.
Take this following example of the NFL's Week 4 matchup between the New England Patriots and hosting Kansas City Chiefs:
Examining the moneyline column, Kansas City is tipped at -278, while New England is at +260. What exactly does this imply? Well, to understand odds in this style, you just need to consider what the digits are in relation to a $100 bet. These numbers carry specific implications.
If the Patriots achieved the upset at +260 odds, that implies you would net $260 if you bet $100. Should the Chiefs win and you bet their moneyline, it'd require a larger wager to gain a substantial payout. That -278 number means you'd need to stake $278 just to win $100.
Teams are typically favored for a cause, and the greater the distance from +100 a favorite is, the better their chances of success are. With that, however, bettors are accepting more risk in the way that the heavier the favorite, the bigger the bet is needed to make a decent profit. It's important to weigh these risks.
Consider this Patriots-Chiefs clash on the backburner of your mind, because we'll revisit it and unpack a few other applicable numbers from the above snapshot. For now, we'll proceed to the other categories of odds and where you're inclined to encounter them.
Despite being less prominent than American odds, it's useful to know what you're looking at when it comes to fractional odds. They're pretty easily converted from American odds anyway, and on a sport-by-sport basis, you're bound to encounter fractional odds most when it comes to horse racing.
We'll have a full-blown tutorial and guide to betting horses, but to put it succinctly: each horse will have odds before the race. Here's the final odds for the 2020 Kentucky Derby, with fractional odds included
Fractional odds can either be written with a slash or a hyphen. They mean the exact same thing. In this instance, you can see how much of a favorite Tiz the Law was prior to the Run for the Roses. Alas, a different script played out at Churchill Downs, as Authentic beat out Tiz the Law as they finished in the top two, with long shot Mr. Big News managing to finish in third place.
Finally, we have decimal odds, which are very similar to fractional odds, except without the aid of a denominator. You're essentially just taking fractional odds and doing the math, which results in a more abbreviated version, expressed as a single integer.
Although major U.S. sportsbooks don't opt for a decimal odds format the vast majority of the time, you may see it on a betting ticket itself. Take this epic winner from a DraftKings bettor, whose ticket here is shown with decimal odds
Some apparently clairvoyant person (robot?) nailed a ridiculous string of bets and won over $6,000 off a $25 bet. You can see the decimal odds on the betting ticket expressed as 249.5. It takes some working backwards to understand that number in the proper context. All you have to do is divide the winnings by the amount wagered:
$6,237.51 / 25 = 249.5 decimal odds
How do these convert to fractional and American odds? All you have to do for the former is subtract one and divide by one, which comes out to 248.5/1 fractional odds. For the latter, you keep that 248.5 figure from the fractional odds, but then you convert that to a positive odds number and carry over the decimal point by two places: +24850.
In other words or aloud-speak, the odds of winning that nine-leg parlay were 248.5-to-1. That's a dizzying amount of synchronicity or astral alignment or whatever that is. Transcendence into Sports Betting Apex Form? How about we call it a beacon of hope that anyone can be a big winner.
If that word "parlay" threw you off, fear not. Those will be addressed in due time later in this article, but first, one final, even less common way to think about how to read odds — only in this case, you may have to do some math of your own. Unless you use abe.
Here's where that Patriots-Chiefs game comes back into play. All implied probability means is the chances a team has to win expressed as a percentage out of 100 in relation to what their listed odds are. Even that might sound long-winded. No worries — we have calculations prepared for you.
For favorites, such as Kansas City, here is the formula to find the implied probability, followed by the Patriots' odds plugged in and the resulting calculation. Bear in mind, you're disregarding the negative sign in KC's odds, and just using the whole number to plug into the formula:
Implied probability = odds / (odds +100) * 100 = --> -278/(278+100) = .735 * 100 = 73.5% implied probability
For underdogs, such as New England, the formula is a little different:
100 / (odds + 100) = implied probability --> 100/(260+100) = 100/235 = .277 * 100 = 27.7% implied probability
The implied probability numbers are rounded up to the nearest whole number in most instances you see them (Chiefs: 74%; Patriots: 28%). It's just easier to track that way. When you can find an implied probability that's lower than what you think the chances should be, that's a good indication it's time to put a bet down.
Say you love K.C. to crush New England, and think the Chiefs' chances of winning are even better than 74%. That -278 moneyline doesn't seem like an appealing wager, and that's where it might be worth looking into the point spread instead, since it's only a touchdown or so.
Thankfully, implied probability is probably the only instance where bettors really need to calculate odds. In all other instances, sportsbooks should crunch the numbers for you and adjust the numbers based on however much money you want to throw down.
Now we're going to look at the two other main bet types beyond the moneyline discussed earlier: the point spread and the Over/Under, or Total. Here's the Patriots-Chiefs screen grab again for reference
Next to the spread, there's often a number between +100 and -110. In this instance, abe's odds give you the best deal across the major sportsbooks, but chances are, you'll see it closer to or at -110. These odds put the bettor at a slight disadvantage, as the bookmaker is taking a little bit off the top of a bet, which is referred to as "juice" or "vig."
These American odds work the same way as before. All it means is, if you were to bet on the Patriots' +3 point spread at -105 on FanDuel, you'd need to wager $105 to win $100. If you visited SugarHouse and bet on the Chiefs to cover at -6.5, you'd have to bet $109 to win $100.
For Over/Under bets, the principle is the exact same as the spread in that the odds you see are probably in the ballpark of -110, at least prior to a game starting as opposed to a live bet situation. Therefore, again, it'll take a $110 investment to win $100 on either side of the Total. This Pats-Chiefs particular Over/Under of 52.5 is quite high, which makes sense considering they both have dynamic quarterbacks in Cam Newton and Patrick Mahomes, both of whom have won NFL MVP honors.
Well, when we converted the decimal odds before, it turns out the best example derived from a parlay. If that section was at all confusing to you, perhaps the visual aid of the betting slip helped. If not, all you need to know is that a parlay combines more than one bet onto a single betting ticket, and you must hit all "legs" of the bet to earn the payout.
The advantage of parlays is you increase the betting odds, which can translate to a massive payout on even a minimal bet if you can hit it. Of course, it's a lot harder to nail three or four bets all at once as opposed to just wagering on a single game, or betting on each of those games separately.
Teasers are forms of parlays where you take greater control of your destiny. Instead of letting the bookmaker decide how many points each team will win the game by in your parlay, you get to apply an alternative point spread to all the teams on your parlay — aka "tease" them together — and can either increase or decrease the odds by doing that. Below is an example of a teaser from DraftKings, which we discuss in more detail elsewhere on our "How to Bet" hub
DraftKings gives you the option to increase or decrease the point spread by certain amounts, and the odds adjust accordingly. If you choose your teams to cover by more points, the odds go up, and if you afford them a bigger cushion relative to the spread, the odds go down.
Reading the odds is, well, more than half the battle. Once you have a good grasp on that, you can proceed to bet. It's really rather straightforward, and if you get a few days of betting under your belt, it'll come easily. It also helps that the sportsbooks do the math on your wager amounts to show you how different odds give you different payouts. Odds are an expression of your chances of winning, and in whatever form they come in,
Now, what's great about using abe is you can consult our odds comparison engine and earn the highest possible payouts on all your bets. Yes, it takes some effort to create multiple sportsbook accounts and keep track of them, yet the more you have open, the better your chances of finding the best odds through us are.
Plus, we have all kinds of promo deals thanks to our partnerships with the major U.S. sportsbooks that give you either deposit bonuses, massive free bets or both when you sign up to create a new account. It's a no-brainer to take advantage of all this, and abe itself is free to use. The odds are listed in American style, and you can input your desired wager on our site to see how your payouts vary by sportsbook before you make a final decision about your bets.