Odds converter

How it works

Fractional odds are still the traditional format in UK betting shops and racing, while most sites let you switch to decimal and US sources use American odds. This converter translates between all of them in one step.

Decimal: includes your stake. At 2.50, every unit staked returns 2.50 in total, a 1.50 profit.

Fractional: shows profit relative to stake only. 3/2 means you win 3 for every 2 staked; 1/1 is evens.

American: a + number is the profit on a 100 stake; a − number is what you must stake to win 100. The minus sign marks the favorite.

Implied probability: the chance the price represents, before removing the bookmaker’s margin.

Formulas

• Decimal = fractional + 1 (3/2 → 1.5 + 1 = 2.50)
• American, if decimal ≥ 2: + (decimal − 1) × 100
• American, if decimal < 2: − 100 ÷ (decimal − 1)
• Decimal from American: +A → A ÷ 100 + 1; −A → 100 ÷ A + 1
• Implied probability = 1 ÷ decimal × 100

Worked example

Odds of 3/2 are 2.50 in decimal, +150 in American and an implied probability of 40.00%. A £100.00 bet returns £250.00 (£150.00 profit). In the other direction, 4/5 is 1.80 in decimal, −125 in American and 55.56%.