How do I convert fractional odds to decimal?

Divide numerator by denominator, then add 1. Example: 9/2 = (9÷2)+1 = 5.5. The +1 accounts for returned stake.

What does implied probability mean?

100 divided by decimal odds. Represents probability of winning as priced by the bookmaker, including their margin.

How do American moneyline odds work?

Positive shows profit per €100 bet. Negative shows how much to bet to win €100. +250 = €250 profit. -200 = bet €200 to win €100.

Which odds format for matched betting?

Always use decimal odds in calculators. Most exchanges use decimal. Switch bookmaker settings to decimal if possible.

Odds Converter - Decimal, Fractional, American

Enter Your Odds (Converts Automatically)

Fraction

Enter as fraction

Decimal

European format

American (Moneyline)

US format

Implied Probability

Probability percentage

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Odds Conversion Table

Fraction	Decimal	American (Moneyline)	Implied Probability
1/10	1.10	-1000	90.91%
1/5	1.20	-500	83.33%
1/4	1.25	-400	80.00%
1/3	1.33	-303	75.19%
2/5	1.40	-250	71.43%
1/2	1.50	-200	66.67%
4/6	1.67	-149	59.88%
4/5	1.80	-125	55.56%
1/1	2.00	100	50.00%
6/5	2.20	120	45.45%
5/4	2.25	125	44.44%
6/4	2.50	150	40.00%
7/4	2.75	175	36.36%
2/1	3.00	200	33.33%
5/2	3.50	250	28.57%
3/1	4.00	300	25.00%
4/1	5.00	400	20.00%
5/1	6.00	500	16.67%
6/1	7.00	600	14.29%
10/1	11.00	1000	9.09%

Format Definitions - Odds and Probabilities

Fractions

Fractional odds show the potential profit relative to the stake. For example, 5/1 means you win €5 for every €1 staked, plus your stake back.

Decimal

Decimal odds represent the total return including your stake. For example, 2.50 means you get €2.50 back for every €1 staked.

American - Moneyline

American odds use positive and negative numbers. -200 means stake €200 to win €100. +150 means win €150 from a €100 stake.

Implied Probability

Implied probability converts odds into a percentage chance of the outcome. Decimal odds of 2.00 imply a 50% chance.

How to Convert Odds and Probabilities - FAQ

To convert odds to probability percentages:

From Decimal: Probability = (1 / Decimal Odds) × 100. Example: 2.00 = (1/2.00) × 100 = 50%
From Fraction: First convert to decimal, then use the decimal formula. Example: 1/1 = 2.00 = 50%
From American: For negative odds: Probability = (Odds / (Odds - 100)) × 100

Divide the numerator by the denominator and add 1. For example, 5/2 = (5 ÷ 2) + 1 = 3.50.

Positive American odds show profit per €100 staked. Negative odds show how much to stake to win €100. For example, +200 means €200 profit on €100 stake, -200 means stake €200 to win €100.

Different bookmakers and regions use different odds formats. An odds converter helps you quickly compare odds across platforms and understand the true value of a bet regardless of how it's displayed.

An odds converter translates betting odds between decimal, fractional, American (moneyline), and implied probability formats. Enter odds in any format to see all equivalents instantly.

Odds Conversion Formulas

Fractional to Decimal

(Numerator ÷ Denominator) + 1. Example: 5/2 = 2.5 + 1 = 3.50

Decimal to Implied Probability

100 ÷ Decimal odds. Example: 3.50 → 28.6% implied probability

Decimal to American

If ≥ 2.0: (Decimal − 1) × 100 (positive). If < 2.0: −100 ÷ (Decimal − 1) (negative). Example: 3.50 → +250. Example: 1.50 → −200.

Common Mistakes When Converting Odds

✕
Forgetting the +1 when converting fractional to decimal. 5/2 is NOT 2.5. It is (5÷2)+1 = 3.5. Decimal always includes the returned stake.
✕
Confusing negative American odds direction. −200 means the favourite (bet €200 to win €100). +200 means the underdog (bet €100 to win €200).

Always use decimal odds when entering values into matched betting or surebet calculators. Most exchanges already display decimal odds.