Odds Format Converter

Convert Decimal, Fractional, American and Implied Probability odds formats instantly.

Decimal▶

e.g. 1.91, 2.50

Fractional◀

UK style, e.g. 10/11, 5/2

American◀

Moneyline, e.g. -110, +250

Implied probability◀

0%–100%

Presets

On a £1 stake

Decimal

2.00

Profit

£1.00

Breakeven win-rate

50.00%

Implied prob.

50.00%

Formulas

Decimal ↔ Implied: p = 1 / d, d = 1 / p

Decimal → American: if d ≥ 2: A = +100·(d−1); else A = −100/(d−1)

American → Decimal: if A ≥ +100: d = A/100 + 1; if A ≤ −100: d = 100/|A| + 1

Fractional: d = 1 + num/den. Converting decimal → fractional uses the best rational approximation with denominator ≤ 1000 (continued fractions).

Converts betting odds between Decimal, Fractional, American and Implied Probability formats. Ideal for comparing odds across bookmakers, understanding different markets and working with betting models that use different odds formats.

Information only. Check all calculations before placing bets. Odds and market conditions may change. Bet Tools HQ accepts no responsibility for losses arising from reliance on these results.