Betting Odds Converter and Payout Calculator


This piece will teach you everything you need to know about different types of odds, the math behind them, and additional info that ought to help you out.

If you’re here just to convert some odds, that’s fine, too. Even though there are many odds converter/calculator tools out there, we believe ours is the simplest one—and the best-looking one too, come to think of it.

Betting Sites With the Best Odds

Before you can start converting odds you’ll need to find some odds. Below are some of our favorite online betting sites for 2021. If you have more questions about what makes a betting site worth your business be sure to check out our page on the best online sportsbooks.

Having an online sportsbook that provides competitive odds is hugely important!

Betting odds represent the very basis of sports betting. Understanding them is the key to becoming a successful bettor. Knowing how to convert different odds, calculating the probability percentages, and understanding the math behind breaking even; these are the best weapons you can have in your sports betting arsenal. This know-how will drastically increase your profits, but learning everything does require both hard work and plenty of time.

If you’ve come here looking for legit information on sports betting odds and the math behind the system, you’re at the right place!

Odds Conversion Chart

American Fractional Decimal Implied Odds
-500 1/5 1.20 83.3%
-450 2/9 1.22 81.8%
-400 1/4 1.25 80%
-350 2/7 1.29 77.8%
-333.3 3/10 1.30 76.9%
-300 1/3 1.33 75%
-275 4/11 1.36 73.3%
-225 4/9 1.44 69.2%
125 5/4 2.25 44.4%
137.5 11/8 2.38 42.1%
900 9/1 10.00 10%
1000 10/1 11.00 9.1%
2000 20/1 21.00 4.8%
5000 50/1 51.00 2%
10000 100/1 101.00 1%
100000 1000/1 1001.00 0.1%

How to Use Our Betting Odds Calculator

Here’s a two-step guide for everyone using our betting odds calculator for the first time:

  • First, enter the odds into one of three available spots: American (US, moneyline), Decimal (EU), Fractional (UK). This will convert them to the two other types of odds and give you the implied probability.
  • If you want to calculate the win and payout amounts too, enter the amount of money you wish to invest into the Bet Amount ($) box. Keep in mind that $100 is the minimum amount.

For more information on betting odds and conversion, check out the following video:

    Fractional Odds

    Fractional odds, commonly known as UK odds, are represented by a fractional setup (e.g. 3/1) and are commonly used for betting on sports.

    American Odds

    American odds, commonly known as US or moneyline odds, are represented by either a negative or positive line depending on the probability of both outcomes (e.g. +160, -225).

    Decimal Odds

    Decimal odds, commonly known as European odds, are represented by a decimal number (e.g. 1.44) and are widely used not just in the EU but all across the world, too.

The Math Behind Converting Betting Odds

There’s plenty of math here; betting odds are just numbers, and the math is there to ensure they all make perfect sense! Whether we’re talking about simple odds conversion, implied probability, or other calculations, math is ever-present.

If you’re serious about wanting to become a successful sports betting enthusiast, you can’t keep relying on online calculators.

You have to be able to switch fractional to decimal, American to fraction, and everything in between within seconds.

It might seem complex, but once you understand what these numbers mean (Mason), we’re sure it won’t take too long for you to figure out the sports betting math.

American Odds Conversion

American to Decimal

For positive odds:

  • Formula: 1 + (American Odds / 100)
  • Example: +350 | 1 + (350 / 100) = 4.5
For negative odds:

  • Formula: 1 – (100 / American Odds)
  • Example: -160 | 1 – (100 / -160) = 1.63

American to Fractional

For positive odds:

  • Formula: American Odds / 100
  • Example: +300 | 300 / 100 = 3/1
For negative odds:

  • Formula: -100 / American Odds
  • Example: -200 | -100 / -200 = 1/2

Decimal Odds Conversion

Decimal to Fractional

  • Formula: Decimal Odds / 1 – 1
  • Example: 5 | 5/1 – 1 = 4/1

Decimal to American

For positive odds:

  • Formula: (Decimal Odds – 1) x 100
  • Example: 3.5 | (3.5 – 1) x 100 = 250
For negative odds:

  • Formula: -100 / (Decimal Odds – 1)
  • Example: 1.25 | -100 / (1.25 – 1) = -400

Fractional Odds Conversion

Fractional to Decimal

  • Formula: Fractional Odds + 1
  • Example: 5/4 | 5/4 + 1 = 2.25

Fractional to American

For positive odds:

  • Formula: Fractional Odds x 100
  • Example: 4/1 | 4/1 x 100 = 400
For negative odds:

  • Formula: -100 / Fractional Odds
  • Example: 1/4 | -100 / 1/4 = -400

Converting Odds to Implied Probability

Now, let’s turn our focus away from betting odds conversion and towards implied probability calculations! But first and foremost, what is implied probability?

It represents the behind-the-odds probability of a winning bet. It’s easier to explain it with an example.

For Example:
A bet with odds -300 (decimal 1.33, fractional 0.33/1) has an implied probability of 75%. This percentage means that the bet is supposed to win three of four occasions.

Understanding implied probability and being able to convert it from American/decimal/fractional odds on the fly will help you better assess the value of any given match.

The formula for calculating IP via American odds:

Positive odds:

  • 100 / (American Odds + 100) x 100 to result in a percentage
Negative odds:

  • American Odds divided by (American Odds + 100) x 100 to result in a percentage (eliminate negative symbols in front of American Odds)

Betting Odds Calculator FAQ

If you’re too lazy to find your answers in the above-featured number-bomb, here’s a nice little shortcut that ought to help you out.

If you want to learn how to convert fractional to positive American odds, all you have to do is take the value of fractional odds and multiply it by 100 (e.g., 3/1 times 100 equals 300).

To convert fractional to negative American odds, you have to divide -100 by the value of fractional odds (e.g., -100 divided by 1/5 equals -500).

If you want to learn how to convert decimal to positive American odds, you have to subtract one from the decimal value, then multiply it by 100 (e.g., 3.2 minus 1 multiplied by 100 equals 220).

To convert decimal to negative American odds, you have to divide -100 by the decimal value minus 1 (e.g. -100 divided by 1.5 minus 1 equal -200).

The formula for calculating implied probability via American odds is as follows.

For positive odds, you’ll want to divide 100 by the sum of American odds and 100. Multiply the result by 100 to get the IP percentage.

For negative odds, take the American odds value divided by the sum of American odds value and 100, and multiply it by 100 to get the result in a percentage. Eliminate both negatives in the formula (by multiplying by -1), otherwise, you’ll get the wrong results.

You can use our sports betting odds calculator for virtually all forms of sports betting. Heck, you can even use it for betting on esports too. The math is always the same, no matter what sort of a competition/discipline we’re talking about. The numbers don’t change. But other variables do, so you need to be in the know if you want to get some quick and easy returns.