Decimal vs Fractional vs American Odds
The same price can look like 3.0, 2/1 or +200. Here's how to read all three odds formats and convert between them in seconds.
Odds come in three main formats — decimal, fractional and American — and the same bet can be written in any of them. UK bookmakers traditionally use fractions, most modern sites default to decimals, and US sportsbooks use the +/- 'moneyline' style. Knowing all three, and how to switch between them, means you'll never be confused by a price again. This guide shows you how each works and how to convert on the fly, building on how betting odds work.
Decimal odds (the clearest format)
Decimal odds show your total return per £1 staked, including your stake. Odds of 3.0 return £3 for a winning £1 bet; odds of 1.5 return £1.50. To find your profit, subtract 1 from the decimal and multiply by your stake.
Decimals are the easiest format for judging value because the implied probability is simply 1 ÷ odds. That's why most tipster records and our own evaluation guides use them.
Fractional odds (the UK tradition)
Fractional odds like 2/1 ('two to one') show your profit relative to your stake, excluding the stake itself. 2/1 means £2 profit for every £1 staked; 1/2 means £1 profit for every £2 staked (an odds-on favourite). Add the two numbers and divide to convert: 2/1 = (2÷1) + 1 = 3.0 decimal.
Fractions are still standard in horse racing, so if you follow a racing service you'll see them constantly — our horse racing tipsters page uses this world.
American (moneyline) odds
American odds use a plus or minus sign. A positive number (+200) is the profit on a £100 stake, so +200 = 3.0 decimal. A negative number (-150) is how much you must stake to win £100, so -150 = 1.67 decimal. You'll mostly meet these on US sports and exchanges.
They look intimidating but follow simple rules, and any decent odds converter turns them into decimals instantly.
Quick conversion cheat-sheet
To compare prices fairly, convert everything to decimals: fractional → (numerator ÷ denominator) + 1; American positive → (odds ÷ 100) + 1; American negative → (100 ÷ odds) + 1. Once everything is decimal you can read implied probability at a glance.
Getting comfortable with formats is the groundwork for spotting when a tipster inflates their record with unrealistic prices — a trick we expose in tipsters who change odds after posting. Then compare services fairly on their Trust Score.
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TipsterCheck's editorial team independently researches sports betting tipsters and betting markets. We don't sell tips and we never take payment to influence a rating — our guidance is built on transparent track records, verified user reviews and our published scoring methodology.
Last reviewed 17 August 2026 · Written and fact-checked against our review policy and scoring methodology.
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