Decimal Odds

Decimal odds are the standard format used outside the US — common in Europe, Australia, and on most betting exchanges and prediction markets. They express the total return per dollar staked, including the original stake.

How They Work

A decimal price tells you how much you’d receive in total per $1 wagered.

• 2.50 = $1 bet returns $2.50 ($1 stake + $1.50 profit)
• 1.91 = $1 bet returns $1.91 (the equivalent of -110 American)
• 3.00 = $1 bet returns $3.00 (a 2-to-1 payout, equivalent to +200 American)
• 2.00 = $1 bet returns $2.00 (even money, equivalent to +100 American)

The implied probability of a decimal price is just 1 ÷ decimal_odds. So 2.50 implies a 40% probability (1 ÷ 2.50). 1.91 implies 52.4%. This makes the math cleaner than American odds for many calculations.

Why It Matters

Decimal odds are the default format on betting exchanges (Novig, Betfair) and most prediction markets. They’re also standard on international books, which means anyone doing comparison work across global pricing references will encounter them constantly.

Many serious bettors prefer working in decimal regardless of their region because:

• Implied probability is trivially easy to calculate (just divide 1 by the odds)
• Multi-leg parlay math is straightforward — multiply the decimals together
• Cross-book comparisons don’t require switching between two formulas (one for negative American, one for positive)

For converting between American and decimal: positive American becomes (odds ÷ 100) + 1; negative American becomes (100 ÷ |odds|) + 1. So +200 → 3.00, and -150 → 1.67.

For more on odds formats, see How Betting Odds Work.