Odds converter
This converter turns any betting odds into decimal, fractional, American and implied probability, and shows the return and profit on your stake in Rands. Decimal odds of 2.75 are 7/4 fractional, +175 American and a 36.4% implied chance; a R100 bet returns R275, including your stake.
How the odds converter works
Pick the format you have, type the odds, and enter your stake. The calculator converts everything through decimal odds, because every other format maps neatly onto them:
- Decimal → fractional: subtract 1 and express the rest as the simplest fraction. 2.75 − 1 = 1.75 = 7/4.
- Decimal → American: at 2.00 or above, (decimal − 1) × 100 with a plus sign; below 2.00, −100 ÷ (decimal − 1). So 2.75 is +175 and 1.50 is −200.
- Implied probability: 100 ÷ decimal odds. 2.75 implies 36.4%.
- Return: stake × decimal odds. Profit: return − stake.
If you switch the format, the odds you typed are rewritten in the new format, so you can flip between them to check a price.
A worked example in Rands
Say a bookmaker offers Kaizer Chiefs to beat Orlando Pirates at 2.75, and you want to stake R100.
- Fractional: 7/4 (win R7 for every R4 staked).
- American: +175 (win R175 profit on a R100 stake).
- Implied chance: 36.4%.
- Return: R100 × 2.75 = R275, of which R175 is profit.
Now look at the whole market. If the draw is priced at 3.10 and a Pirates win at 2.50, the implied chances are 36.4% + 32.3% + 40.0% = 108.7%. The 8.7% above 100% is the bookmaker’s margin, also called the overround. The lower that figure, the better value the market offers, which is one reason to compare prices across sites in our best betting sites list.
Why implied probability matters
Odds are a price, not a prediction. If you think Chiefs win this match 45% of the time and the price implies 36.4%, the bet has value in your view; if you think it is 30%, it doesn’t. Converting to a percentage makes that comparison simple. Be honest with yourself, though: bookmakers set prices with a lot of data, and the margin means the average bettor loses over time.
Related tools
To combine several selections, use the bet and accumulator calculator, which multiplies the legs and shows the return. If you are using a free bet or a deposit bonus to bet, the wagering calculator shows what the bonus terms will cost. Our free bets page lists the current offers and their minimum odds rules.
Bet only what you can afford to lose and never chase losses. Free, confidential help is available from the NRGP on 0800 006 008.
Frequently asked questions
How do I convert fractional odds to decimal?
Divide the first number by the second and add 1. So 7/4 is 1.75 + 1 = 2.75, and evens (1/1) is 2.00.
What is implied probability?
It is the chance of an outcome that the odds suggest: 1 divided by the decimal odds. Odds of 2.50 imply 40%. Because bookmakers build in a margin, the implied chances in a market add up to more than 100%.
Which odds format do South African betting sites use?
Most South African bookmakers, including Hollywoodbets, Betway and Supabets, show decimal odds by default. Horse racing is still often quoted in fractions, such as 5/1.
What is the difference between return and profit?
Return is everything paid back on a winning bet, including your stake. Profit is the return minus the stake. A R100 bet at 2.75 returns R275, which is R175 profit.
What do negative American odds mean?
A minus sign shows the favourite: -200 means you must stake R200 to win R100 profit (decimal 1.50). A plus sign shows how much profit a R100 stake wins: +150 is decimal 2.50.
Mark has been writing about online gaming since 2007, covering everything from sportsbooks to casino and slot reviews, offering insights for players of all levels.