Fractional Odds Calculator

Input fractional odds such as 7:2 or 11:4 and a stake amount to analyze implied probability and returns.

Enter as a ratio. Denominator must be positive.

Decimal odds: 3.750

Implied probability: 26.67%

Total payout if win: 37.50

Profit if win: 27.50

How to Use This Calculator

  1. Enter fractional odds as a:b (e.g., 11:4).
  2. Provide a stake amount.
  3. Review decimal odds, implied probability, payout, and profit.
  4. Compare values across bets or convert to decimal form for analysis.

Formula

Fractional odds a:b → decimal = (a / b) + 1

Implied probability = b / (a + b)

Payout = stake × decimal odds

Profit = payout − stake

Full Description

Fractional odds (common in the UK) describe profit relative to stake. For example, odds of 7:2 mean a £2 stake returns £7 profit plus the stake (£9 total). This calculator translates fractional odds into decimal form and quantifies expected returns.

Frequently Asked Questions

Can fractional odds be inverted?

Yes. Odds of a:b correspond to odds of b:a for the opposing outcome.

What if I need American odds?

Convert to decimal odds first, then apply formulas for American odds.

Do fractional odds include stake?

No. They describe profit relative to stake. Decimal odds include stake.

How accurate are results?

Calculations follow exact arithmetic; results assume no bookmaker margins or fees.