# Odds converter

Convert decimal, fractional, and American odds with implied probability.

Canonical URL: https://stats-api.com/tools/odds-converter

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Convert decimal, fractional, and American odds with implied probability. Calculations stay in your browser and are not betting advice.

Converted result

Bookmakers publish the same price in three incompatible notations. Decimal dominates in Europe and Australia, fractional persists in UK horse racing, and American (moneyline) is standard in the United States. They encode identical information; only the arithmetic differs.

## The conversions

- Decimal → implied probability: `p = 1 / d`
- Fractional → decimal: `d = (numerator / denominator) + 1`
- American positive → decimal: `d = (odds / 100) + 1`
- American negative → decimal: `d = (100 / |odds|) + 1`

## Worked example

A price of **2.50** decimal is **3/2** fractional and **+150** American. Each says the same thing: stake 2 to win 3, for a total return of 5. The implied probability is 1 / 2.50 = **40%**. A price of **1.50** decimal is **1/2** fractional and **−200** American, implying 66.7%.

## The trap most people hit

Fractional odds quote *profit*, decimal odds quote *total return*. 3/2 and 2.50 look unrelated until you notice the decimal figure includes your stake back. This is the single most common source of off-by-one-stake errors when porting a betting model between markets.

## Doing this at scale

Converting one price by hand is arithmetic. Converting every price for every fixture is a data problem: you need fixtures, teams and stable identifiers to attach prices to. Stats API supplies the fixture and team layer with identifiers that do not change between requests, so your odds pipeline has something durable to key against.

## Common questions

### Which odds format should an API return?

Decimal. It converts to probability with a single division, has no sign convention to handle, and avoids the fraction-reduction ambiguity where 10/4 and 5/2 are the same price written two ways.

### Why does +150 not equal −150?

American odds are asymmetric by design. A positive number is the profit on a 100 stake; a negative number is the stake required to profit 100. +150 implies 40%, −150 implies 60%.

Related tools

- [Implied probability calculator](https://stats-api.com/tools/implied-probability)
- [Kelly criterion calculator](https://stats-api.com/tools/kelly-calculator)
- [Poisson football score predictor](https://stats-api.com/tools/poisson-score-predictor)
- [Football kickoff time converter](https://stats-api.com/tools/kickoff-time-converter)
- [Football league table generator](https://stats-api.com/tools/league-table-generator)

Build with the API

- [API quickstart](https://stats-api.com/docs)
- [Football data API](https://stats-api.com/football-api)
- [Competition coverage](https://stats-api.com/coverage)
- [Betting model use case](https://stats-api.com/use-cases/betting-models)

For developers

## Turn the idea into an integration.

This utility is intentionally client-side and does not require an account. When your product needs real competition, team, fixture, or result data, use the documented Stats API endpoints and your own API key.

[Read the API quickstart →](https://stats-api.com/docs)

*The live page also has interactive controls that need a browser: https://stats-api.com/tools/odds-converter*

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