Decimal to Fractional Odds Converter

The formula

The base formula is straightforward; the only tricky part is reducing the fraction to its smallest whole-number form:

Step 1 — subtract 1. Profit ratio = Decimal − 1
Example: 2.50 → 1.50
Step 2 — express as fraction. Fraction = profit ratio (e.g. 1.50 = 1.5/1 = 3/2 or 6/4)
3/2 and 6/4 are equivalent; UK racing books usually prefer 6/4. Most online tables display the simplest form.

Conversion table

Common odds across all three formats. Use this as a quick reference; the calculator above handles any value to four decimal places of precision.

Decimal	American	Fractional
1.10	-1000	1/10
1.25	-400	1/4
1.40	-250	2/5
1.50	-200	1/2
1.67	-150	4/6
1.75	-133	3/4
1.83	-120	5/6
1.91	-110	10/11
2.00	+100	1/1 (Evens)
2.10	+110	11/10
2.25	+125	5/4
2.50	+150	6/4
3.00	+200	2/1
3.50	+250	5/2
4.00	+300	3/1
5.00	+400	4/1
6.00	+500	5/1
11.00	+1000	10/1
21.00	+2000	20/1
51.00	+5000	50/1
101.00	+10000	100/1

When to use decimal odds

Decimal odds are everywhere online and standard outside the UK. They are easier to compare across markets — higher number always means longer odds.

When to use fractional odds

Fractional odds remain the default at British and Irish high-street bookmakers, racecourses, and ITV/Sky Sports racing broadcasts. The Cheltenham Festival, Royal Ascot, and the Grand National all post prices in fractions. Some legacy UK punters strongly prefer fractions because they show profit-per-stake immediately.

Frequently asked questions

What is decimal 2.00 in fractional?

2.00 = 1/1, called "Evens" or "Even Money" in the UK. A £10 bet returns £20 total.

Why is 2.50 sometimes shown as 6/4 and sometimes as 3/2?

Both are mathematically identical. Traditional UK racing books prefer 6/4 because punters at the track are used to those denominators (4ths, 8ths). Online tables tend to show the lowest-terms version, 3/2.

How is fractional odds at less than evens shown?

For favorites (decimal between 1 and 2), the fraction inverts to "odds-on": e.g. decimal 1.50 = 1/2 ("one-to-two on", you risk 2 to win 1). Decimal 1.25 = 1/4. Decimal 1.10 = 1/10.

Why does 11/4 appear on some boards but not others?

Quarter-fractions (5/4, 7/4, 9/4, 11/4, 13/4 etc.) are the traditional UK racing odds ladder. Online sportsbooks may convert the same decimal price to a different fraction (e.g. 11/4 ≈ decimal 3.75 ≈ +275 American), so always cross-check.