Betting Math Calculator

Free betting math calculator to convert betting odds formats. Instant results in your browser — no signup.

JavaScript is required for live calculation.

You can still read how Betting Math Calculator works, the formula, examples, and FAQs below.

Odds value — Decimal like 2.50, or American like -110 / +150
From format

Direct calculator

Enter values and calculate an instant answer.

Convert

From

Unit

Result

2.500

Results update when you click Convert.

Decimal odds

2.500

American+150
Fractional3/2
Implied probability40.00%

Recently used

Tools you open will show up here on this device — with your last inputs when available.

What this result means

Free betting math calculator to convert betting odds formats. Instant results in your browser — no signup. American +A → 1+A/100; −A → 1+100/|A|. Implied % = 100 ÷ decimal.

Assumptions

Rule dependency: Game/sport rules may vary.

Formulas

American +A → 1+A/100; −A → 1+100/|A|. Implied % = 100 ÷ decimal.

Example

Decimal 2.50 = American +150 = 3/2 fractional.

Frequently asked questions

What does this betting odds formats calculator do?+

It helps you convert betting odds formats. Typical search: “odds converter”.

How should I read the result?+

Convert betting odds formats using decimal/fractional/American odds. Result: converted odds.