Decimal vs Fractional vs American Odds (with Conversion Table)
Where each odds format came from, a two-way conversion table, the six formulas that link them, the Asian formats you will meet online and the mistakes people make reading American prices.
Decimal 2.25, fractional 5/4 and American +125 are the same price written three ways. None is more generous than the others. This page is the reference: where each notation came from, the six formulas that link them, a table you can read in either direction, and the Asian formats you meet on international sites.
In short.
- Decimal shows total return per unit staked; fractional and American show profit only.
- Fractional to decimal: divide and add one. American plus: ÷100 and add one. American minus: 100 ÷ the number, add one.
- A minus sign in American odds marks a favourite, not a bigger price — −160 is shorter than +125.
- Hong Kong odds are simply decimal minus one; Indonesian odds are American divided by 100.
- Convert everything to decimal before comparing prices or multiplying legs. Nothing else compares cleanly.
Part of the series
For what a price means rather than how it is written, see how to read betting odds. The percentage hidden inside every number here is the subject of turning odds into probability.
Where the three notations came from
Each format was built for a different job, which is why none of them died out.
- Fractional grew out of British racecourse betting, where a bookmaker called a price as profit against stake: 5/1 meant five units of profit for one risked. It is spoken language first — "five to one", "evens", "odds on".
- Decimal came from continental Europe and became the default once betting moved to screens: one number you can sort, multiply and compare without thinking. Exchanges and almost every app in Nigeria use it.
- American is built around a 100-unit reference: the profit a 100 stake makes, or the risk needed to make 100. It suits two-way sports priced close together, which is what United States sportsbooks mostly sell.
The six formulas
Three conversions into decimal and three back out. Learn the first three and you can read any price you meet.
- Fractional to decimal: numerator ÷ denominator + 1. So 5/4 = 1.25 + 1 = 2.25.
- American plus to decimal: number ÷ 100 + 1. So +125 = 1.25 + 1 = 2.25.
- American minus to decimal: 100 ÷ the number + 1. So −160 = 0.625 + 1 = 1.625.
- Decimal to fractional: take decimal − 1 and write it as a fraction. 2.75 − 1 = 1.75 = 7/4.
- Decimal to American, price 2.00 or above: (decimal − 1) × 100. So 3.50 gives +250.
- Decimal to American, price below 2.00: −100 ÷ (decimal − 1). So 1.44 gives about −225.
The break at 2.00 is the only awkward part. Evens is +100 in American and 1/1 in fractional, and anything shorter flips to a minus sign.
The conversion table
| Decimal | Fractional | American | Implied probability | Return on ₦500 |
|---|---|---|---|---|
| 1.20 | 1/5 | −500 | 83.3% | ₦600 |
| 1.44 | 4/9 | −225 | 69.4% | ₦720 |
| 1.625 | 5/8 | −160 | 61.5% | ₦812.50 |
| 1.91 | 10/11 | −110 | 52.4% | ₦955 |
| 2.00 | 1/1 | +100 | 50.0% | ₦1,000 |
| 2.25 | 5/4 | +125 | 44.4% | ₦1,125 |
| 2.75 | 7/4 | +175 | 36.4% | ₦1,375 |
| 3.50 | 5/2 | +250 | 28.6% | ₦1,750 |
| 6.00 | 5/1 | +500 | 16.7% | ₦3,000 |
| 11.00 | 10/1 | +1000 | 9.1% | ₦5,500 |
Read it either way: find your price in any column and the rest of the row is the same bet. Fractional prices follow a customary list of steps, so 1.83 is shown as 5/6 rather than as a fraction nobody quotes.
Example. A friend sends a screenshot from an American site with two selections at −160 and +125. Converted, that is 1.625 and 2.25. On ₦500 each, the first returns ₦812.50 (profit ₦312.50) and the second ₦1,125 (profit ₦625). As a double, 1.625 × 2.25 = 3.66, so ₦500 returns ₦1,828.13.
Which format you meet where
- Nigerian apps and most of the world: decimal, often with no option to change it.
- British and Irish racing, and television coverage: fractional, more often spoken than written.
- United States sportsbooks, NBA and NFL commentary: American.
- Asian handicap markets: Hong Kong, Malay or Indonesian.
Hong Kong, Malay and Indonesian odds
These appear on sites that grew out of Asian handicap betting. Each is a rewrite of a format you already know.
- Hong Kong is decimal minus one — pure profit per unit. HK 1.25 is decimal 2.25.
- Malay is positive up to 1.00 for short prices (profit per unit staked) and negative for long ones, where the figure is the stake needed to win one unit. Malay −0.40 means risk 0.40 to win 1, so decimal 3.50.
- Indonesian is American divided by 100. Indo +1.25 is +125 is decimal 2.25; Indo −1.60 is −160 is decimal 1.625.
| Decimal | Hong Kong | Malay | Indonesian |
|---|---|---|---|
| 1.44 | 0.44 | +0.44 | −2.25 |
| 1.91 | 0.91 | +0.91 | −1.10 |
| 2.00 | 1.00 | 1.00 | +1.00 |
| 2.25 | 1.25 | −0.80 | +1.25 |
| 3.50 | 2.50 | −0.40 | +2.50 |
| 6.00 | 5.00 | −0.20 | +5.00 |
Reading American prices without getting caught
Almost every mistake with odds formats happens in the American column, for one reason: the sign carries meaning that people read as size.
- Minus means favourite. −160 is a shorter price than +125, even though 160 is the larger number.
- A minus price is a stake, not a profit. −200 means risk 200 to win 100, so a ₦500 stake profits ₦250, not ₦1,000.
- Small-looking gaps are not small. −105 is 1.952 and −115 is 1.870 — a difference of 4.4% on every naira you stake.
- American odds cannot be added. To price a double or an accumulator, convert every leg to decimal and multiply.
- −100 and +100 are the same price. Both are 2.00, and sites usually show the plus version.
Important. Changing the display format never changes a bet you have already placed. If the payout looks different after you switch, the price itself moved while you were looking — check the slip before confirming rather than after.
The habit is simple: whatever arrives on your screen, convert it to decimal before judging it, then compare with the market on our fixture pages.
FAQ
Which odds format is best?
Decimal, for anything involving a calculation. It shows the total return per unit, sorts correctly, and multiplies straight across an accumulator. Fractional and American carry exactly the same information but need a conversion step before you can compare or combine prices.
Why does my app show 5/6 when another site shows 1.83?
Because fractional notation uses a customary ladder of steps rather than every possible ratio. 5/6 is 1.833 in decimal, so the two agree, but the fraction cannot express the small differences between 1.83, 1.85 and 1.87 that decimal shows directly.
How do I convert a fractional price like 11/8?
Divide and add one: 11 ÷ 8 = 1.375, so the decimal price is 2.375 and a ₦500 stake returns about ₦1,188. In American notation that is +137 or +138 depending on rounding, which is one more reason to keep the decimal figure as your working number.
Do Asian formats offer better prices?
No. Hong Kong, Malay and Indonesian odds are notations, not products, and a site using them can be dearer or cheaper than any other. Convert to decimal and the comparison becomes obvious in a few seconds.
This article is for information only and is not an inducement to gamble. Betting involves the risk of losing money — never stake more than you can afford to lose. 18+. If gambling stops being entertainment, read our responsible gambling guide and seek help.
