Value Calculator: Work Out Bet Expectation

One of the key concepts you need to understand as a punter is the relative value of a bet.

You can now judge the value of any bet, by using this Value Calculator, which takes a single bet and its probability of success and then calculates the likelihood of that bet turning you a profit (or loss) if repeated over 100 times. The greater the profit shown then the greater the value of the bet.

Odds Probabilty % Value

How to Use the Value Calculator

Here’s how to use it:

Entering the Odds

The first piece of information the calculator needs from you is the odds of your chosen bet. All you do in this first box is enter the odds of the market you want to back.

So let’s say for this example, we want to back Manchester United to beat Chelsea at the weekend at odds of 11/10. You would simply enter 11/10 in the Odds box.


So where do you find the probability of an event listed? In short you can’t.

Probability is just the chances of an event happening.

For example, guessing the correct card from a pack of 52, is a 51/1 chance of success, whereas guessing whether a coin will land heads or tails is about a 50/50 (even money) chance of success.

What you must do here is compile some research into your sporting event to come up with a realistic probability figure for your chosen bet.

As well as reviewing stats, take a keen interest in the events leading up a sporting event. If your bet is on a horse race, are the stable and trainer in form? Is the jockey winning races? Will weather conditions affect the ground in favour of your selection or against it? In a soccer match, look at the injuries and suspensions to see if key players will be playing or omitted, who is the referee, what will the weather be like?

By taking as broad a view as is practically possible, you can come up with an educated guess at a probability figure.

So going back to our example…

Let’s say you conduct some research into the Manchester United v Chelsea fixture and discover that all the stats point to a very good chance of a home win for Manchester United. Taking all things into consideration, you’d then calculate that United are around 75% certain to win the match.

You then enter this figure into the probability box next to the odds and click on the blue Calculate button.

Remember, probability is not an exact science, it is down to your judgement, but by thoroughly researching your market, you give yourself a much better chance of making a more accurate judgement and thus, getting a better reflection of the true value of a bet.


Once you have clicked the blue Calculate button, the relative value of the bet based on the odds and probability is then calculated, with the result shown in the value box.

In our example above, the value of the Man Utd v Chelsea bet at 11/10 with a probability of around 75% of success is rated at 57.50.

Any positive figure represents a value bet, while any minus figure, represents a bet that is not good value, but what does this number actually mean?

Positive Value Figure v Negative Value Figure

What the Value Calculator does is calculate, based on the odds and the probability of an event succeeding, the long term value of a bet. In short, if the bet was placed 100 times, how often would it win and how much potential profit would that generate for the punter.

Therefore, any positive figure means the bet offers value as if the punter placed the same bet a 100 times, then they would turn a profit.

A negative figure however implies that this is not a good value bet as if the punter placed the bet 100 times, it would see them lose money.

The higher the positive figure, the greater value a bet is.

In our example above, we saw that our bet on Manchester United to beat Chelsea offers a little value, but if the odds on a Manchester United win were shorter, or their chances of success in winning were smaller (or a combination of both these factors) then this would change.

Let’s now say that the odds on Manchester United winning have shortened to 8/13 but after reviewing the data, we feel United’s chances of success are now around 50%, rather than 75%.

With this new data, the value of the bet is reversed. Now over 100 bets, we are forecast to make a loss of £19. Therefore, with these new odds and probability figures, this is not a value bet.

The Value Calculator is a good way to ensure that the bets you make offer decent value, both in terms of return and potential success, but key to its functionality and reliability, is the amount of research you put in to ensure your probability figure is as accurate as possible.