How to Read Betting Odds: American, Decimal & Fractional

Every set of odds answers two questions at once: how likely the bookmaker thinks an outcome is, and how much you win if it happens. Those two things are the same number expressed differently, so once you can read one you can read them all.

The same bet is quoted in three formats around the world — decimal (Europe, Australia, Canada), fractional (UK, Ireland, horse racing) and American (US sportsbooks). None of them is "better"; they're just different languages for the same price. WagerBeasts lets you switch the display format from the settings, so pick the one you read fastest and the whole site follows.

Decimal odds show your total return per $1 staked, including your stake back. A price of 2.50 means a winning $10 bet returns $25 — that's your $10 back plus $15 profit.

The quick formula is: Return = Stake × Odds. So $20 at 1.80 returns $36 ($16 profit). Anything below 2.00 is an odds-on favourite (you risk more than you stand to win); anything above 2.00 is an underdog.

Because the math is just multiplication, decimal is the format most bettors use for comparing prices and calculating value — and it's why most of the examples on this site use it.

Fractional odds show profit relative to stake, not total return. 5/1 ("five to one") means you win $5 for every $1 staked, plus your stake back — so $10 returns $60.

The trap is odds-on prices written backwards, like 1/2 ("two to one on"): that's $1 profit for every $2 staked. A $10 bet returns $15.

To convert fractional to decimal, divide the fraction and add 1: 5/1 → 5 + 1 = 6.00; 1/2 → 0.5 + 1 = 1.50. That single step lets you compare a UK price against everything else.

American odds use a + or − sign and are built around a $100 unit.

Positive (+150) = profit on a $100 stake. +150 means a $100 bet wins $150 profit. These are underdogs.

Negative (−200) = the stake needed to win $100. −200 means you must risk $200 to win $100. These are favourites.

To go to decimal: for positive odds, (odds ÷ 100) + 1 → +150 becomes 2.50. For negative odds, (100 ÷ odds) + 1 → −200 becomes 1.50. The break-even line is +100 / −100, which is exactly 2.00 in decimal.

This is the single most useful skill in betting. Implied probability = 1 ÷ decimal odds. A price of 2.00 implies a 50% chance (1 ÷ 2.00). A price of 1.50 implies 66.7%. A price of 4.00 implies 25%.

Why it matters: it lets you compare the bookmaker's opinion to your own. If you think a team has a real 60% chance to win but the price implies only 50% (2.00 or better), that's a potential value bet — the payout is bigger than the true risk warrants.

You'll also notice the implied probabilities of all outcomes in a market add up to more than 100%. That extra slice is the bookmaker's margin, or vig — the built-in commission. Learning to spot it is what the next two guides are about.

Even money = 2.00 decimal = 1/1 fractional = +100 American. Double your money.

Odds-on favourite = below 2.00 / below evens / negative American. More likely than not; small payout.

Underdog = above 2.00 / above evens / positive American. Less likely; bigger payout.

Don't memorise conversion tables — just remember 1 ÷ decimal = probability and the two American formulas. Everything else follows. When you're ready, the natural next step is learning why the *same* bet pays differently at different books, and how to always take the best price.