Odds Converter

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How it works

The odds converter instantly converts fractional, decimal and moneyline odds into your chosen format and gives you the implied probability of the event occurring. For more information on betting odds and how they work, please see my Betting Odds Explained guide.

Odds formats explained

Fractional odds

These are the odds traditionally used by bookmakers and show you how much you win relative to your stake.

The number on the left is how much you win based on staking the amount on the right. For example, fractional odds of 9/1 show that you stand to win £9 for every £1 staked.

With fractional odds, you also get your original stake back. In the 9/1 example, you win £9 plus your original £1 stake you handed over to the bookmaker for a total return of £10. Some more examples are below.

Decimal odds

Decimal odds show how much a winning bet will return, including your stake. You multiply your stake by the odds to get your total returns.

So, if you bet £1 on England to win the World Cup at odds of 10.00, you’ll get £10 back, which includes your £1 stake.

The main benefit of decimal odds is that they are much easier to compare at a glance. Take decimal odds of 3.75 and 3.60; it’s clear that 3.75 gives a higher return. But which offers the higher return out of 11/4 and 13/5? As such, professional bettors vastly prefer decimal odds.

Betting exchanges display their odds in decimal form, whereas online bookmakers favour fractional odds by default. You can change to decimal odds on your bookmaker settings page for ease of comparison.

Moneyline odds

Moneyline odds (AKA American odds) are shown as positive and negative numbers. A positive value of +500 says you’ll win $500 for every $100 staked. A negative value of -200 says you must stake $200 to win $100.

Like fractional odds, they do not include your stake, so add this back at the end. For example, +800 gives $800 back from a $100 stake. Adding your original $100 stake gives a total return of $900.

Implied probability

Implied probability is the conversion of betting odds into a percentage. It gives you a rough idea of how likely something is to happen.

The actual probability of an outcome happening is usually slightly less than the implied probability, as betting odds factor in the bookmaker’s margin. Bookmakers offer odds that they believe are lower than the actual chances of something happening, which is how they make their money over the long term.

Odds conversion table

A quick reference chart featuring all the traditional odds used by bookmakers.

* Decimal odds are shown to two decimal places but are not rounded, as this is how they appear on a bookmaker’s site.

Can you use betting odds to gain an advantage over a bookmaker?

Yes, there are numerous ways to make the odds work in your favour to win more from bookmakers than you lose.

One of the most popular is a tried and tested technique called matched betting. When bookmakers offer a free bet or promotion, they effectively put the odds in your favour and allow you to make money from them in the hope that you will keep betting and lose money in the long term.

Matched betting exploits this. When a bookmaker offers a free bet, you can cover all outcomes of an event to claim the free bet for an overall loss of just pennies. You then have a free bet to use. You can either hope this wins or repeat the process of covering all outcomes to extract about 80% of the free bet amount. You can make about £16 profit from a £20 free bet, no matter the outcome of your bets. Bookmakers know this opportunity exists but continue to offer free bets and promotions as they know most people will bet casually and go on to lose money.

My comprehensive and free Matched Betting Guide will take you through the basic concept with a complete walkthrough of your first bookmaker promotion. You’ll even earn about £15 in the process.

Beyond that, my Matched Betting Academy details how to profit from every UK bookmaker’s ‘welcome’ offer, all for free. Designed and tested by matched betting experts, it also provides techniques to make money from extra place offers, 2UPs, price boosts, and other recurring existing customer offers, all logically structured and well-paced.

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