Odds converter calculator

Price Input format Decimal Fractional American Hong Kong Indonesian Malay

Enter fractional prices as 3/2.

Example result

2.50 decimal equals 3/2, +150 and 40.00% implied probability.

What this calculator answers

Enter one price and its format. The calculator expresses the same price in the other common formats and shows the implied probability before any margin adjustment.

Formula and worked example

Formula: Decimal = 1 + fractional numerator divided by denominator. Implied probability = 100 divided by decimal odds.

At decimal 2.50, implied probability is 100 divided by 2.50, or 40.00 percent. The equivalent fractional price is 3/2 and the American price is +150.

Checks before using the result

• Entering a fractional price as a decimal number changes the meaning.
• Treating implied probability as a forecast ignores the market margin.
• Malay and Indonesian signs matter, so check the displayed sign.

When the calculation does not apply

It does not remove a market margin or account for settlement rules. Use the overround calculator when several outcomes are available.

Keep the number in context

A calculator makes the arithmetic visible, but it does not decide whether a price fits your budget or information. Write down the stake before placing anything, check the market rules, and keep essential money separate. The result is a planning figure, not a prediction of what will happen.

For another view, visit the calculator hub, compare the Accumulator and Arbitrage, or read the guide to reading odds. These tools use the same price conventions, so you can check a number from more than one angle.

Reading a rounded result

Displayed money amounts are rounded to two decimal places, while a real settlement can apply its own rounding sequence. Keep the original inputs beside the result if you need to repeat the calculation later.

If an input is unclear, pause and find the stated market term rather than guessing. A useful check is to change one input by a small amount and see whether the result moves in the direction you expect.

That does not validate the market, but it can reveal a reversed sign, an incorrect price format or a duplicated stake. Use the final figure as an aid to understanding the arithmetic, not as a reason to ignore a limit you set in advance.