Sports betting odds: fractional, decimal and American examples

Sports betting odds describe the price of a selection and its potential payout. They do not reveal the result in advance. Fractional, decimal and American formats can express the same price; this guide explains each using hypothetical cash stakes in pounds.

Fractional odds: calculate profit first

At fractional odds a/b, a winning cash stake S earns profit of S × a/b. Add the stake to obtain the total return. A hypothetical £10 stake at 3/1 earns £30 profit and returns £40 if it wins; if it loses, the £10 stake is lost. At 1/5, a winning £10 stake earns £2 profit and returns £12. Evens, or 1/1, gives equal profit and stake.

The fraction describes profit relative to the stake, not a guaranteed chance of winning. A selection below evens is not automatically the favourite across every market; compare the other outcomes in the same market.

Decimal odds: the stake is already included

For a winning ordinary cash bet, total return equals stake × decimal odds. Subtract the stake to find profit. Thus £10 at 4.00 returns £40, including £30 profit. To convert a/b fractional odds, divide a by b and add one: 3/1 becomes 4.00, while 1/5 becomes 1.20. To convert decimal D back, express D − 1 as a fraction.

A larger price means a larger potential payout for the same winning cash stake; it does not prove that the quoted chance reflects the true probability. The price also does not settle eligibility, void-bet treatment or special promotional-stake conditions.

Which format can you select on bet365 UK?

Bet365’s UK account-preferences help, checked on 2 October 2026, lists fractional and decimal displays. On the sports site, scroll to Settings at the bottom and select Odds Display. Alternatively, use My Account → Preferences → Odds Display. Choose the format you can check accurately; changing it does not improve the price. That page does not establish an American-format setting for UK customers.

Comparing prices without mistaking a format for value

Compare the identical selection, market, period and settlement terms before judging two quotes. Convert the prices into the same format so presentation does not disguise a difference. Neither an operator name nor a bonus code proves that a price offers value; a code does not increase the advertised offer. Calculating a payout is not evidence that the bet should be placed.

American odds: reading the plus and minus signs

American odds use a plus or minus sign to describe the profit relative to a reference amount of 100. You do not have to stake £100, and the format does not require dollars. This guide uses hypothetical cash stakes in pounds so UK readers can compare the same price with fractional and decimal odds.

What the plus sign means

At +200, a winning £100 cash stake earns £200 profit and returns £300 in total. For any stake, multiply it by 200/100 to calculate profit. A £10 stake at +200 therefore earns £20 profit and returns £30 if it wins. If it loses, the £10 stake is lost.

For positive American odds A, decimal odds equal 1 + A/100. At +200, that gives 3.00 decimal or 2/1 fractional. The +200 figure represents profit per 100 staked, not total return.

What the minus sign means

At −150, the reference calculation is £150 staked to earn £100 profit. For an arbitrary stake, profit equals stake × 100/150. A winning £30 cash stake earns £20 profit and returns £50. The minus sign does not mean you lose money when the selection wins.

Use the magnitude of negative odds, ignoring the sign in the denominator: decimal odds equal 1 + 100/|A|. At −150, this is exactly 5/3, displayed as about 1.67. The exact fractional equivalent is 2/3, not an approximate fraction.

Equivalent prices in three formats

Return includes the cash stake; profit does not. The rounded penny figures illustrate the conversion and are not a promise about a named operator’s rounding or settlement. Retain full precision through a multiple calculation, then round the final illustrative amount.

The sign alone does not identify the favourite

Positive odds imply a price above evens; negative odds imply one below evens. In a two-outcome market, a bookmaker margin can produce two negative prices, such as −110 on each side. That does not make both outcomes the favourite relative to one another. Compare the complete market and prices rather than assigning favourite or underdog solely from the sign.

Implied probability is not a forecast

For +A, implied probability is 100/(A + 100). For −A, using the positive magnitude A, it is A/(A + 100). Thus +200 implies 33.33%, while −150 implies 60%. These are price-derived break-even figures, not independently measured chances of the event happening.

Two opposing −110 prices each imply about 52.38%, totalling roughly 104.76%. That total illustrates a bookmaker margin; it is not a contradiction requiring both outcomes to occur. Changing the display format does not remove that margin, improve the price or prove that a bet offers value.

Using American prices in a multiple

Convert each permitted selection to its exact decimal equivalent before multiplying. A hypothetical £10 double at +200 and −150 uses 3.00 × 5/3 = 5.00 combined decimal odds: £50 total return and £40 profit if both win. Neither leg alone pays out in an ordinary losing double. Related-event combinations and settlement adjustments need their own rules.

See the BCP calculator guide for stake and return checks, or the accumulator guide for linked selections. This page does not assume an American-odds setting is available on every UK product or that a particular calculator supports it.

Source checked on 1 October 2026: the calculation section of bet365’s US House Rules confirms that American, decimal and fractional displays can describe the same price, including −500 = 1.20 = 1/5. It is cited only for odds-format equivalence, not UK eligibility, currency, promotional or settlement rules. The pound examples and probability figures above are independent arithmetic.

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