Hawkplay: Odds Formats Explained — Converting Step by Step

Converting between odds formats step by step means treating a price as a number you can take apart, not a signal to trust blindly. Decimal, fractional and American are the three main odds formats in use, and once you can move between them, you can read the implied probability and the bookmaker’s margin behind any Philippine sportsbook price. Decimal odds explained here is the baseline every other format on this page converts from.

Decimal Odds Explained: Start Here

Decimal odds are the price format most commonly displayed in Philippine-facing sportsbooks, and every other format on this page converts from it. A decimal price already includes the stake in the number: 2.50 means a winning ₱100 stake returns ₱250 in total, ₱150 profit plus the ₱100 stake back.

Odds Formats: Why Convert Between Them

A price displayed in one format hides the same information a price displayed in another format shows plainly. Fractional odds show a ratio of profit to stake; American odds show how much you’d win on a ₱100 (or $100) reference stake; decimal odds show total return per unit staked directly. Converting between them is how you compare a price quoted one way against a price quoted another way on the same outcome.

Odds Conversion Table

Decimal	Fractional	American	Implied probability
1.50	1/2	−200	66.7%
2.00	1/1	+100	50.0%
2.50	3/2	+150	40.0%
3.00	2/1	+200	33.3%
4.00	3/1	+300	25.0%

Converting Decimal to Fractional

Convert any decimal price to a fraction in two steps:

1. Subtract 1 from the decimal price.
2. Write the result as a fraction over 1, then simplify.

Decimal 2.50 → 2.50 − 1 = 1.50 → written as 3/2. Decimal 1.50 → 1.50 − 1 = 0.50 → written as 1/2. A fractional price of 3/2 means a winning stake of 2 units profits 3, matching the decimal price exactly once the stake is added back.

Converting Decimal to American

Convert any decimal price to American format in two steps:

1. If the decimal price is 2.00 or above, multiply (decimal − 1) by 100.
2. If the decimal price is below 2.00, divide −100 by (decimal − 1).

Decimal 2.50 → (2.50 − 1) × 100 = +150. Decimal 1.50 → −100 ÷ 0.50 = −200. All three formats — decimal 2.50, fractional 3/2, American +150 — describe the identical price.

Implied Probability and the Overround

Implied probability is a percentage estimate read directly off a price, and comparing it across every outcome in a market is how you find the bookmaker’s margin. A two-way market with both sides at decimal 1.91 implies 1 ÷ 1.91 ≈ 52.4% per side. Add the two sides together: 52.4% + 52.4% = 104.8%. Because real outcomes can only total 100% between them, the extra 4.8 percentage points is the margin built into the price, not a measurement error or a rounding artefact.

Putting the Conversion to Work

Once you can convert a price and read its implied probability, three things become easier:

1. Comparing a price across sportsbooks that each display a different format, using the sports betting Philippines pillar as the reference for what a price encodes.
2. Judging your stake and payout before you bet, rather than after settlement — the bet settlement spoke covers what happens once the result is confirmed.
3. Spotting bookmaker margin quickly, since implied probability is the fastest way to see it, the way the 104.8% two-way market example above did.

Terms like implied probability and margin are also defined in the the casino terms list.