How to Read Betting Odds

There are several betting odds systems. Check out this guide to learn how to read betting odds efficiently and to figure out which profits they offer.

A Brief Guide to Reading Betting Odds

It’s 1795 and the first bookmaker opens their door at a horse racing venue in the United Kingdom. Even today, two centuries and two decades later, the legality of it is still an issue. In November 2018, Rhode Island became only the eighth US state that has legalized sports betting. Many huge sports organizations (the National Football League for one) are against nationwide betting legalization, as they see it as a door for corruption and match-fixing. Others, however, are rooting for it, since it would massively thin out illegal bookies.

Nevertheless, nowadays, betting on sports is a widespread activity people enjoy throughout the world. If you’re a sports fan, placing a bet makes it only that more interesting and gives you a personal reason to closely follow the results of various sporting events. Our parents did it on broadcast Teletext, now we have apps for it; but all the same, the adrenaline rush while waiting for that last-second shot to go in is still there.

Sports betting odds (and gambling odds at that) is what bookmakers use to mathematically express your chances of winning and how much money you stand to win betting on those chances. When you first lay your eyes on them, it’s difficult to discern how to read betting odds in front of youIt seems confusing what the odds represent and how much you can win, but it’s actually quite simple.

There are several systems for determining how much money you’ll receive by guessing the right outcome, with the most common one being the American odds.

American Odds

Also known as the moneyline odds, this system offers you both positive and negative odds you use to determine who wins the game. It’s easy to spot right off the bat who the favorites are. Positive odds are reserved for the underdogs, and they represent how much money you will get if you bet $100. On the other hand, negative money line bets go with the team that’s expected to win, and it represents how much money you need to bet in order to win $100.


For example, in the Super Bowl LIII, the New England Patriots were sitting at −135, while the Los Angeles Rams were at +115. These odds read as follows: If you wanted to earn $100 by predicting a Pats win, you’d need to place a bet worth $135. It’s a worse return of money, but it’s a safer option (who knew the ‘Deflatriots’ were going to win it again).

If, however, you placed $100 on the Rams, you’d win $115 (in hindsight you wouldn’t because they failed to score a single touchdown, but those were the chances).

NB: you don’t have to bet $100. This is just a round number people use to easily calculate the odds and so that everyone’s on the same page. For instance, you could have placed $5 on the Pats, which would get you $3,70 in profit (that’s $8,70 in total).

Point Spread

A point spread (which bettors also call the handicap) is a system used for giving an advantage (or disadvantage) to a certain team. This basically means that (in their eyes) the game didn’t start at 0:0 but with an advantage. For example, a point spread bet in the Super Bowl was −2.5 on the Patriots. This signifies that, in order to win, the Pats had to win by three or more points; a 10:8 final score wouldn’t suffice.

Of course, a point spread bet puts you more at risk, but you can win more money that way.

 Super Bowl

Fractional Odds

Fractional, or the UK, odds are—you’ve guessed it—most popular in the United Kingdom. They represent the odds in—you’ve guessed it yet again—fractions. Basically, you have two numbers in it, as every odd takes the format of x/y. X represents how much money you’ll win if you bet Y. Plus, of course, the amount of money you’ve wagered.

For example, if Manchester United stands at 10/15 to win against Arsenal, that translates into winning $10, should you put in $15 (the actual payout would be $25, but the profit is clearly $10). On the other hand, Arsenal’s odds of 5/1 places them as the underdogs. This means that it’s five times as likely they’ll lose than they’ll win. With that in mind, if you place $1 on it, you stand to win $5. Of course, this scales accordingly if your bet rises. Put in $5, get $25 (not that Arsenal would actually win, but hey, stranger things have happened).

To calculate between the American and fractional odds, you can use the following pattern. Positive American odds become odds/100. For instance, a +200 translates to 200/100, which is a 2/1 fractional odd. Negative odds are just reciprocal: 100/odds.

Decimal Odds

Decimal odds are becoming more and more popular due to the fact that they’re simpler than the fractional ones. This system actually seems to be the easiest to calculate. You get an odd, and you just multiply it with the money you intend to put in.

For example, in the World Cup 2018 final, Croatia faced France. Croatia ended up in their first ever World Cup final and they became the sweethearts of the tournament with their unexpected string of wins. When the final game arrived, everyone rooted for the underdogs (except for, obviously, the French and probably some of their neighboring countries). As underdogs—a title they vindicated by losing 4:2—their odds were 4.20. Meaning that if you had placed a $5 bet on the Croats, you would have hoped to win $21 (which would be a $16 profit).

France, as the favorites, had a lower decimal odd, standing at 2.00. As you can see, it’s a fairly straightforward system where it’s easy to figure out your possible earnings. The lowest possible odd in this system is 1.01, where you would earn just $1 when wagering $100.

Hong Kong Odds

Hong Kong Odds

Sports betting is highly developed in Hong Kong. There, they use a decimal odds system of their own, which derives from the United Kingdom’s fractional system. This shouldn’t come as a surprise if you know a bit about the historical ties these two entities share. As such, its decimals can go below 1.01. For example, a fractional odd of 2/5 (where you win $2 for every $5 wagered) translates into an HK odd of 0.4. To calculate the winnings, you just have to add 1 at the beginning and get the decimal odd counterpart (an HK of 0.4 is a decimal odd of 1.4).

Calculating Probability

The odds that bookmakers give out are not there just to figure out how much money you might win. It’s a mathematical system that you can use to develop your own sports betting algorithm.

For example, if San Antonio Spurs chances of winning are at +120, you’ll get to the implied probability by using this formula: 100/(120+100), which equates to 0.4545. Therefore, the probability of Spurs winning the match is 45,45%.

The same goes for fractions. Odds of 4/1 translate to a 20% chance of winning (100/(4+100) equals 0.20).


Once you get to know how these varying systems function, it’s easy to figure out what chances of winning you have and what kind of profit you can look forward to. When betting online, many of the sportsbooks contain these most common odds, so you don’t have to calculate them yourself.

It’s tricky at first, but once your brain gets accustomed to translating odds into profits, it won’t represent an obstacle anymore, and you’ll enjoy ways you can make money betting online.

What Do the Odds of +200 Mean?

The +200 is an example of the American odds system. It is mostly used in regards to the team, which is thought to have fewer chances of winning. So the +200 is a way to say that if you bet $100, you will get $200 if your prediction turns out to be right.

How Do Bookies Calculate Odds?

The result of odds calculations can be achieved after the comprehensive analysis of many factors. Put it shortly, odds are something of an average of the stats, history, opinions (polls), latest events, etc. The more data they take into consideration, the more precise the odds will be. It is necessary to mention though, that sports bookmakers subtract their margin from the odds. For example, that could be 5%. So they add this commission to each probability and then count the odds not out of 100% as you would normally suggest, but out of 110%.

What’s the Difference Between Probability and Odds?

Probability is just another way of writing down the odds. Most people tend to understand the chances described in probabilities better than in various odds systems. That might be happening because probability clearly shows changes in percentages. For example, Team A has a 20% probability of winning, while Team B has an 80% probability of winning. If you find it hard to understand the odds, you can find an online odds to probabilities converter and simply translate the odds into probability.

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