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 shows the arithmetic. It doesn't tell you whether the price fits your read of the outcome or your budget. Decide the stake before you enter it. Check the market rules. Keep essential money out of it entirely.

Cross-check on a second tool. The calculator hub, Accumulator or Arbitrage cover the same numbers from a different angle. Same price conventions, so a decimal price in one is a decimal price in the other.

Read the guide to reading odds if you're new to the formats. Two minutes.

Reading a rounded result

Money is rounded to two decimals here. A real settlement applies its own rounding sequence, which can differ. Keep the original inputs written down if you're going to check the number later.

Unclear about an input? Find the stated market term. Don't guess. A quick sanity check: change one input by a small amount and see whether the result moves the way you expect.

That doesn't validate the market. It can flag a reversed sign, a mis-entered price format or a duplicated stake. Use the number to understand the arithmetic. It's not a reason to ignore a limit you set in advance.