Betting Odds: Three Formats, One Conversion and Implied Probability

Good in every season and at every book: this reference converts betting odds among the three formats a Philippine bettor is likely to see, and shows how to read the chance a price implies. Each format states the same bet in different words, which is why one conversion is enough to compare offers. All peso amounts here are hypothetical arithmetic and use a ₱100 stake, so each row can be compared at a glance.

Betting odds formats side by side

Read a row across and you have one bet written in five ways. Decimal includes the stake in the return; fractional and Hong Kong show only the profit, which is why they are 1 lower than decimal when written as a number.

How to convert betting odds

1. Decimal to Hong Kong: take 1 away, so decimal 2.50 minus 1 gives Hong Kong 1.50.
2. Hong Kong to decimal: add 1. Hong Kong 0.91 becomes 1.91.
3. Fractional to decimal: divide the top number by the bottom, then add 1. Fractional 3/2 is 1.5, so 2.50.
4. Decimal to fractional: subtract 1, then write the result as a fraction. Decimal 4.00 leaves 3, so 3/1.
5. Any format to a peso return: convert to decimal first, then multiply by the stake.

Decimal is the safest form for arithmetic, and it is the form to use when you stack several prices into a parlay combined odds sum.

Reading the implied probability

Turn any decimal into a percentage with 1 ÷ price. That is the chance the price assumes, before your own view comes in.

The 4.2% above 100 is the book’s margin. On a fair market the two chances would add to exactly 100%. So a price only represents value when your honest estimate of the outcome is higher than the implied chance after you account for that margin.

Applied to one case: an NBA betting moneyline price of 1.60 needs the team to win more than 62.5% of the time to break even. If you believe the true figure is 60%, the bet loses over time at that price, however good the team looks.

Comparing two books with one number

Say Book A prices a side at 1.87 and Book B shows Hong Kong 0.95, which is decimal 1.95. Both are written differently, and only conversion shows the gap.

That ₱40 difference is the same bet at a better price, and it repeats on every slip you place.

Common mistakes with betting odds

1. Problem: comparing a decimal price with a Hong Kong one. Fix: add 1 to the Hong Kong figure first, or you will read 1.50 as worse than 2.40 when it is really 2.50.
2. Problem: reading fractional odds as a return. Fix: 3/2 is profit against stake, so add the stake back in.
3. Problem: treating implied chance as true chance. Fix: implied figures carry the margin, so they run a little high.

The casino terms list defines the surrounding vocabulary, and the sports betting shelf points to each sport’s markets.