Betting Odds Converter

How it is calculated

Starting from decimal odds (the total return per 1 staked, stake included), the tool gives three equivalents. Implied probability: p = 1 ÷ decimal × 100. Fractional odds: the profit per unit, (decimal − 1), written as a fraction over 100 and reduced by the greatest common divisor. American (moneyline) odds: for decimal odds of 2.00 or more, +((decimal − 1) × 100), meaning profit on a 100 stake; below 2.00, −(100 ÷ (decimal − 1)), meaning the stake needed to win 100. The decimal value must be above 1. The implied probability includes the bookmaker's margin, so the probabilities of all outcomes add up to more than 100%.

Common mistakes

• Taking the implied probability as the true chance of winning. It also contains the bookmaker's margin.
• Confusing fractional 3/2 (profit of 3 per 2 staked) with decimal 3.5 or 1.5. The decimal equivalent is 2.5, because the stake is included.
• Entering odds of 1 or below, which are rejected, or entering fractional or American odds into the decimal field.
• Reading +150 and −150 as mirror images. +150 is 2.5 decimal, while −150 is about 1.67.