Professional Betting Calculators for the Serious UK Punter

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Odds Converter

Instantly convert between Fractional, Decimal and American odds formats. Also calculates Implied Probability — the true winning chance the market is pricing in.

Betfair / European
UK Standard
Moneyline (+/-)
True Win Chance
Now You Know the True Odds. Is the Bet Worth Placing?

Converting odds is step one. Members use Kelly Criterion to calculate the exact stake based on their edge — and Trade-Out to lock in profit when the price moves in their favour.

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Understanding Betting Odds Formats

Bet online and you'll encounter three main odds formats. They all represent the same thing — risk versus reward — but they look very different. Here's what each one means.

The 3 Formats Explained

  • Fractional (e.g., 5/2) — UK Standard. Shows your profit relative to your stake. Bet £2 to win £5 profit (£7 returned in total).
  • Decimal (e.g., 3.50) — Betfair / European. Shows your total return including stake. Bet £1 to get £3.50 back. Generally easier for calculating Dutching and exchange bets.
  • American (e.g., +250) — Moneyline. Used in US sports. Positive (+): profit on a $100 bet. Negative (–): stake needed to win $100. (+250 means bet $100 to win $250. –150 means bet $150 to win $100.)

Why is Implied Probability important?

The green box in this calculator is arguably the most important number in betting. Bookmaker odds are simply a representation of probability expressed as a price.

If a horse is priced at 3/1 (4.0 decimal), the market is saying it has a 25% chance of winning. If you genuinely believe it has a 30% chance, you have found value — and that is the foundation of every profitable long-term betting strategy. Knowing this percentage is also the first step to using the Kelly Criterion — one of the premium tools in the Punters Edge suite.

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Try our free Dutching for Stake or Lucky 15 calculator — or join to unlock the full suite.

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Disclaimer: Conversions are mathematical approximations. Fractional odds are rounded to the nearest standard industry fraction where possible. Always verify your own figures before placing any bets.