Bookmaker Odds Converter

Updated: 07.09.2026

The converter translates odds between three formats: decimal (European), fractional (British) and American. Enter the odds in any format — the converter will instantly show the values in all the other formats and the implied probability.

Odds formats

Three main odds formats are used in betting. Russian bookmakers (Fonbet, Winline, Liga Stavok) work with the decimal format. Fractional odds are common in the United Kingdom, American odds — in the United States.

Decimal (European)

Shows the full payout per rouble staked, including the return of the stake itself. Odds of 2.50 mean: a ₽100 bet returns ₽250 (₽150 profit + ₽100 stake back). The value is always greater than 1.00.

Fractional (British)

Shows only the net profit relative to the stake. Odds of 3/2 mean: for every ₽2 staked you win ₽3 of profit. Plus the stake back — ₽5 in total for every ₽2.

American (moneyline)

A positive value (+150) shows the profit on a 100-unit stake. A negative value (−200) shows how much you need to stake to win 100. Odds of +150 = ₽150 profit on a ₽100 stake. Odds of −200 = you need to stake ₽200 to win ₽100 of profit.

Format comparison table

Example Decimal Fractional American Probability
Heavy favorite 1.25 1/4 −400 80.0%
Favorite 1.50 1/2 −200 66.7%
Even chances 2.00 1/1 +100 50.0%
Underdog 3.00 2/1 +200 33.3%
Big underdog 5.00 4/1 +400 20.0%
Huge underdog 10.00 9/1 +900 10.0%

Conversion formulas

Decimal → Fractional:

Fractional = (Decimal − 1) expressed as a fraction

Example: 2.50 → 2.50 − 1 = 1.50 = 3/2

Decimal → American:

If odds ≥ 2.00: American = +(Decimal − 1) × 100

If odds < 2.00: American = −100 / (Decimal − 1)

Example: 2.50 → +(2.50 − 1) × 100 = +150

Example: 1.50 → −100 / (1.50 − 1) = −200

Decimal → Probability:

Probability = (1 / Decimal) × 100%

Example: 2.50 → (1 / 2.50) × 100 = 40%

Use the margin calculator to work out the real probabilities with the bookmaker's commission factored in, and the value bet calculator to check whether a bet holds value.

Other calculators

More on working with odds — in the article Advanced Betting Strategies.

Frequently asked questions about odds formats
🙋 Which odds format do Russian bookmakers use?
💁 All Russian bookmakers (Fonbet, Winline, Liga Stavok, BetCity, Pari and others) use the decimal (European) odds format. The odds show the full payout per rouble staked, including the return of the stake itself.
🙋 How do I convert American odds to decimal?
💁 For positive odds (for example, +150): divide by 100 and add 1. The result: 150/100 + 1 = 2.50. For negative odds (for example, −200): divide 100 by the absolute value and add 1. The result: 100/200 + 1 = 1.50.
🙋 What does −110 mean in American odds?
💁 Odds of −110 mean you need to stake 110 to win 100 units of profit. In decimal format this is 1.91. This price is typical for vig-bearing totals and handicap lines at US sportsbooks.
🙋 Why are fractional odds still used?
💁 The fractional format is a historical tradition of British horse racing and bookmaking. It intuitively shows the profit-to-stake ratio: 5/1 means 5 units of profit for every 1 unit staked. Many British punters are used to this format, so major bookmakers such as William Hill and Ladbrokes still use it by default.
🙋 How do I find the probability from the odds?
💁 For decimal odds: divide 1 by the odds and multiply by 100. Example: odds of 2.50 → 1/2.50 × 100 = 40%. This is the implied probability, which includes the bookmaker margin. The real probability of the outcome is usually lower.
🙋 Does the odds format affect the payout?
💁 No, the odds format is only a way of writing the price. Decimal 2.50, fractional 3/2 and American +150 all mean the same thing: a ₽100 stake returns ₽150 of net profit. The final payout is identical regardless of the format.