American vs. Decimal vs. Fractional: A Translator for Sports Betting Odds

Understanding betting odds is the key to making smart decisions—whether you’re placing your first punt or switching to a new sports betting platform. This guide breaks down the three main odds formats: American, Decimal, and Fractional. You’ll discover how to read each type, convert between them, and calculate your potential winnings—so you can bet with confidence wherever you play.

Table of Contents

Odds Formats Explained: American, Decimal, and Fractional

When you start betting, you’ll notice odds presented in different ways depending on the site or country. The three most common types are:

American (Moneyline) Odds—e.g. +150 or -120.
Decimal (European) Odds—e.g. 2.50.
Fractional (UK) Odds—e.g. 3/2.

For platforms like Fortunica3 (https://fortunica3.com/en-au), knowing what each format means helps you compare offers and get the best value. To get familiar, here’s a side-by-side summary:

Odds Format	Example	Favored Where	At-a-Glance Meaning
American (Moneyline)	+150 / -120	USA	Shows profit on $100 (underdog) or amount staked to win $100 (favorite)
Decimal	2.50	Australia, Europe	Shows total payout per $1 wagered, including stake
Fractional	3/2	UK, Ireland	Shows net profit per unit staked

Read: Mathematics of Betting Odds

How to Read Each Odds Format

Each odds format presents information differently, but all aim to show how much you can win relative to your stake. Here’s a breakdown to help you understand what to look for in each style:

American:
- Plus (+) Odds (underdog): Amount won for every $100 bet (e.g., +150 means $150 profit on $100 staked).
- Minus (-) Odds (favorite): Amount needed to bet to win $100 (e.g., -120 means risk $120 to win $100).
Decimal: The number shows your total return per $1 bet (including your stake). For example, 2.50 means $1 bet pays $2.50 back ($1.50 profit).
Fractional: Written as A/B (e.g., 3/2). You win A dollars for every B dollars staked (3/2 means $3 profit for every $2 wagered).

Converting Odds Formats: How to Switch and Compare

There are times you’ll need to compare odds or switch formats—especially when hunting for the best lines. Use these simple formulas:

American Odds ↔ Decimal Odds:
- Positive American to Decimal: Decimal = (American Odds / 100) + 1. Example: +150 → (150/100) + 1 = 2.50.
- Negative American to Decimal: Decimal = (100 / |American Odds|) + 1. Example: -120 → (100/120) + 1 = 1.837.
Fractional ↔ Decimal Odds:
- Fractional to Decimal: Decimal = (Fractional Odds) + 1. Example: 3/2 → 1.5 + 1 = 2.50.
- Decimal to Fractional: Fractional = Decimal Odds – 1 (as a fraction). Example: 2.50 – 1 = 1.5 → 3/2.
American ↔ Fractional Odds:
- Positive American to Fractional: Fractional = American Odds / 100. Example: +150 → 150/100 = 3/2.
- Negative American to Fractional: Fractional = 100 / |American Odds|. Example: -200 → 100/200 = 1/27.

Below is a quick conversion table:

American	Decimal	Fractional
+150	2.50	3/2
-120	1.83	5/6
+200	3.00	2/1
-200	1.50	1/2

Calculating Payouts Made Simple

Calculating your potential winnings is crucial before hitting “place bet.” Here’s how each system works:

American odds: For +150: Bet $100 to win $150. Payout = Stake + Profit = $100 + $150 = $250. For -120: Bet $120 to win $100. Payout = Stake + Profit = $120 + $100 = $220.
Decimal odds: Multiply your stake by the decimal odds to get your total return. Example: $40 at 2.50 = $100 return ($40 x 2.50), $60 profit
Fractional odds: Multiply your stake by the fraction to get your profit; add your stake for the total payout. Example: $40 at 3/2 = $60 profit ($40 x 1.5), $100 total return.

Let’s review the payout comparison in the table below:

Format	Odds	Stake	Payout Calculation	Total Return
American	+150	$40	$40 x 1.5 + $40	$100
Decimal	2.50	$40	$40 x 2.5	$100
Fractional	3/2	$40	$40 x 1.5 + $40	$100

Three Common Questions New Bettors Ask

Many beginners struggle with the same odds confusions. Here are some fast answers:

How do I know which team is the favorite? For American odds, the favorite is always negative (e.g. -120), the underdog is positive (e.g. +150). Decimal: lower numbers mean favorite (e.g. 1.50), higher mean underdog (e.g. 3.00). Fractional: smaller fractions (e.g. 1/2) mean favorite, big ones (e.g. 7/2) underdog.
Do decimal odds include my stake? Yes—the number reflects total return, including your bet. American and fractional show only profit.
Is one format “better” than another? Not at all! It’s about clarity and what you find easiest to use.

Essential Tips for Navigating Sports Betting Odds

Before placing your next bet, remember these betting basics:

Double-check which odds format is in use and convert if you’re used to another.
Use online odds calculators to instantly convert and compare across platforms.
Shop around: odds can differ between bookmakers. Compare formats to ensure you’re getting the best deal.
Practise with small stakes as you learn; focus first on understanding payout calculations.
Don’t be swayed by big numbers—always check how much you need to risk to win your target profit.

Bet Smarter by Speaking the Odds Language

Odds can seem confusing at first, but with a bit of practice, American, Decimal, and Fractional odds become second nature. They’re just different ways of expressing the same information: risk, reward, and probability. Learning to read, convert, and calculate payouts will help you make better choices—no matter which sportsbook or platform you use.

Now that you’re fluent in betting odds, try switching formats with your next bet and see which style feels best. And if you’re ready for more guides and platform reviews, jump in and start your journey to smarter, more confident sports betting!

Disclaimer: This article is for informational purposes only. Always ensure that you comply with local laws and regulations regarding online betting. Gambling and iGaming involves financial risk and is addictive. Please play responsibly and within your means. Seek help if you need support.