Odds Calculator

Written by: Brian Webb
Fact checked by Alex Windsor  
Updated: June 12, 2024

Unless you’re a seasoned punter who can compute odds quickly, you need a calculator. Our handy calculator can serve you well if you’re just starting out. Use it to make split-second estimates to work out your exact potential payout using specific and tricky odds values.


What is an Odds Calculator?

The name is self-explanatory. An odds calculator is a specialised digital tool for computing odds values. Odds calculators and betting calculators are terms used interchangeably, but there is a difference. While a betting calculator is an umbrella term that can include various types of tools for calculating betting values, an odds calculator is simpler, yet not less effective.

Such a tool allows you to make instantaneous calculations of your odds and potential payout relevant to your bet amount.

Understanding the Odds Formats

To use an odds calculator, you must have a basic understanding of the three main odds formats.


American odds are represented by a plus/minus sign preceding a number. The “-” (minus) indicates the favourite, while the “+” (plus) is the underdog. If two teams have a minus sign, the one with the bigger figure is the favourite.

The odds for the favourite show you how much you must stake to win £100. For instance, a team with -117 odds requires a bet of £117 to win £100. A team with +200 odds pays out £200 if you wager £100.

Decimal (European)

Decimal odds are easy to calculate. The lower the figure, the bigger the favourite. If Team A has 1.75 odds and Team B 2.85, the former is the favourite. Wagering, for example, £100 on Team A to win will yield a payout worth £175, with a £75 profit.

Fractional (British)

Fractional odds can be identified by a “/” (slash) sign separating two digits. The first digit represents the potential win relevant to the assumed bet, represented by the second digit. For example, odds of 7/2 indicate you will win £7 for every £2 wagered.

Converting Betting Odds with our Free Calculator

The examples above are just that – examples. The odds you’re dealing with can be similar or quite different, and the potential payout will not be easy to estimate, depending on how much you want to stake. Our odds calculator fixes that in seconds.

It is a simple tool with multiple fields where you type/copy specific values. To use it, input the odds in the designated field. The calculator will convert the odds into the available formats and estimate the implied probability. This will show the probability of winning, represented as a percentage value based on the inputted odds.

Our calculator estimates your total potential payout and gain in addition to the implied probability. To do this, you must input your bet amount in the designated textbox.

Why You Should Always Use Our Odds Calculator

Even if you have experience in betting, there’s no shame in admitting your calculating abilities can only go so far. There is a point beyond which you are calculating approximates and rough values when in fact, you need precise calculations. This is where the odds calculator comes most handy.

Many calculators also convert odds. If you’re from the UK, fractional odds are likely what you’ll be dealing with. Using our calculator, you can convert American, decimal, or fractional odds and learn how to read all three formats.

The obvious benefit of using Betting Tools’ odds calculator is the time you save. Using an ordinary calculator can be tricky, and you may find yourself using multiple calculators to compute different values.

Brian is the owner of BettingTools, he has decades of experience in horse racing betting and the best ways to utilize betting tools and calculators. Brian’s vision is to provide a comprehensive resource for bettors, offering sophisticated tools combined with expert advice to enhance betting strategies. He has a passion for horse racing and soccer and a commitment to helping others gain knowledge and succeed in sports betting.