# Odds Calculator

Let’s find out what an odds calculator is and how it works!

## What is an odds calculator?

We’ve previously mentioned that an odds calculator doesn’t so much calculate the odds you might be getting somewhere. Instead, you enter the odds you have found, and the calculator will tell you how much you might win.

They’re usually quite simple, wherever you may find them. Most bookmakers offer them, but plenty of sites about sports betting will also have odds calculators.

## How does an odds calculator work?

Odds calculators have various fields you can fill in: American Odds (-400), Decimal Odds (1.25), Fractional Odds (1/4), Implied Odds (probability = 80%) and your bet size.

Additionally, you may add whether it’s a single or accumulator (parlay) bet, and whether you want to bet each way or not. Some odds calculators are more complex than others.

## What are the different types of odds formats?

As you will notice, there are three different types of formats used when displaying odds: American, Decimal and Fractional. Almost all bookmakers allow you to change the format in your settings. You will find Fractional odds as the default for most UK and Ireland bookmakers. Whilst American odds are the default for American bookmakers.

Let’s have a look at how to read them:

American – These odds are based on winning \$100 on a given bet; odds have usually a minus (-) sign in front of them and indicate the stake you need to bet to win \$100; so, if you have odds of -140, you need to bet \$140 to win \$100; long odds have plus (+) signs in front and indicate that you are essentially betting on the underdog.

Decimal – These odds represent your win for every \$1 bet; so, odds of 1.40 means you win \$0.40 on a \$1 bet; you’ll also get your initial stake back, of course; decimal odds are used in most parts of the world and make it easier to calculate implied odds.

Fractional – These are most difficult to use and therefore only preferred in horse racing; to calculate your return to you need to multiply your bet by the numerator (number at the top) and then divide the result by the denominator (bottom number). If you were to place \$10 on odds of 5/2, your calculation looks as follows: (10x5)/2 = \$25.

## What is implied probability?

Any given odds are calculated based on the probability of an event occurring. So, looking at the odds you can get, the probability is implied.

If you get odds of -140, the implied probability a little over 58%.

Looking at fractional odds of 4/1, the implied probability says that the event you bet on is expected to occur 1 out of 5 times, which equals 20%.

Here’s an odds conversion table for a few odds:

 Fractional Decimal American Implied Probability 1/5 1.20 -500 83.3% 2/9 1.22 -450 81.8% 1/4 1.25 -400 80% 1/3 1.33 -300 75% 4/11 1.36 -275 73.3% 4/9 1.44 -225 69.2% 5/4 2.25 125 44.4% 9/1 10.00 900 10% 100/1 101.00 10000 1%

By the way, when using an odds calculator, your payout in the end usually includes your wins as well as your original stake. So, don’t be irritated when looking decimal odds, for instance, and estimating a different win than what the calculator gives you.