convert_odds: American, decimal, fractional odds and implied probability

convert_odds converts one odds value between American (+150, -110), decimal (2.5), fractional (3/2) and implied probability (0.4 or 40 percent). Give it the odds and their format and it returns all the others. It is pure arithmetic with no data lookup, so +150 always comes back as 2.5 decimal, 3/2 and a 40 percent implied probability.

Examples are real responses from the live server, captured on 1 November 2026.

Parameters

What to ask your assistant

Ask: Use BetsBeats to convert +150 to decimal, fractional and implied probability.

Example request

Send a tools/call request to the endpoint with the tool name convert_odds and these arguments.

{ "odds": "+150", "format": "american" }

Real response

A real response. All four formats come back in one call.

{
  "american": "+150",
  "decimal": 2.5,
  "fractional": "3/2",
  "implied_probability": 0.4,
  "implied_probability_percent": 40,
  "notice": "For adults 21+ only. Entertainment and analysis; no wins are promised and past results do not predict future ones. BetsBeats does not take bets."
}

The math

• American: for +a, decimal = 1 + a / 100. For -a, decimal = 1 + 100 / a, with a as a positive number.
• Fractional n/d: decimal = 1 + n / d.
• Implied probability = 1 / decimal. A probability p converts back as decimal = 1 / p.
• Worked example: +150 gives 1 + 150 / 100 = 2.5, which is 3/2 as a fraction, and 1 / 2.5 = 0.4, which is 40 percent.

Notes

• The value is a string, so pass "+150" with its sign and "3/2" with its slash.
• Implied probability includes the bookmaker's margin. Two sides of a market usually sum to more than 100 percent.
• No data is looked up and nothing is stored. The same input always gives the same output.

Questions

What is implied probability?

The chance the odds break even at: 1 divided by the decimal odds. Decimal 2.5 breaks even at 0.4, or 40 percent.

Can it convert a probability to odds?

Yes. Set format to probability and pass a value such as 0.4 or 40 percent, and it returns the matching American, decimal and fractional odds.

Is there a calculator on the site?

Yes, the odds converter at /odds-converter does the same conversion in the browser.

The other tools

• verify_pick
• get_record
• get_results
• expected_value
• parlay_payout