Fractions, decimals and probability are different ways of presenting the likelihood of an outcome. You might be familiar with the concept of fractional odds because they are the ones you see in the windows of high-street bookmakers.
Fractional odds are mainly used in the UK, but are becoming less popular online due to the difficulty in comparison with other prices. Common ways of writing fraction odds are 4/1, 4:1 and '4 to 1'. The odds displayed show the amount of profit you would receive for a winning bet relative to your stake. A bet of £10 at odds of 4/1 returns £50, £40 of profit and your stake of £10.
Decimal odds are more common online as they provide a simple way of comparing prices between bookmakers and exchanges, and are the standard format used on Smarkets (though all are selectable). Odds in decimals include your return within them, so a bet of £10 at odds of 5.0 returns £50, £40 of profit and your stake of £10.
Moneyline, or American, odds are used mainly by American sports books. If the moneyline is positive then the figure quoted is what you would win based on a £100 bet. If the moneyline is negative then the figure quoted is what you would need to bet to win £100. A £10 bet on a moneyline of +400 returns £50, £40 profit and your stake of £10.
Percentage odds are less common, but display implied probability better than any other system. In this way a £10 bet at 25% returns £50, £40 profit and your stake of £10.
It is possible to manually convert between the different types of odds, but at most sites, including Smarkets, you can display the current prices in any style you wish to make comparison simple. Smarkets defaults to decimals as it is the easiest way of comparing prices, and we do not shy away from our prices as we're confident that what we are offering is the best value betting in the industry.
To make it easier for you, we let you set which type of odds you want shown. Set your choice in display settings.