Odds Conversion Table (US, Fractional & Decimal) With Probability

Generally speaking, odds at crypto sportsbooks are shown in three main formats: American (US), fractional, and decimal odds. While these formats look very different, they all represent the same underlying concept, the implied probability of an outcome occurring.

On this page, you’ll find a comprehensive odds conversion table that lets you quickly compare US, fractional, and decimal odds alongside their implied probability. You’ll also learn how to manually convert between odds formats, so you can understand and calculate prices yourself without relying on an odds converter.

Odds Comparison Table

Below is an odds comparison table covering commonly used betting odds across all three formats, along with their implied probability. The table includes both standard sportsbook prices and extreme short or long odds that are more likely to appear on fast-moving crypto betting markets.

Use this table to convert odds between formats quickly or to understand what any price implies about an outcome’s chance of winning.

How to Convert Betting Odds Manually

All betting odds formats represent the same thing: implied probability. The difference is simply how that probability is expressed. The easiest way to convert between formats is to use decimal odds as the reference point, then convert from decimal into fractional or American odds as needed.

You do not need to memorise multiple formulas for every possible conversion. Once you understand how to move into and out of decimal odds, you can convert any odds format quickly and accurately.

Converting Fractional Odds to Decimal Odds

Fractional odds indicate the profit as a percentage of the stake. To convert them into decimal odds, you add the profit portion to the original stake.

Formula: Decimal odds = (numerator ÷ denominator) + 1

Example: Fractional odds of 3/1

1. 3 ÷ 1 = 3
2. 3 + 1 = 4.00

This means a 1-unit stake returns 4 units in total (3 units profit plus your original stake).

Another example: Fractional odds of 8/13

1. 8 ÷ 13 = 0.615
2. 0.615 + 1 = 1.62

Decimal odds of 1.62 mean that for every 1 unit staked, a total of 1.62 units are returned.

Converting Decimal Odds to Implied Probability

Implied probability indicates the percentage chance of an outcome winning, based on the odds. This is the most straightforward way to compare prices across different sportsbooks and odds formats.

Decimal odds are the easiest format to convert into probability.

Formula: Implied probability = 1 ÷ decimal odds

To express the result as a percentage, multiply by 100.

Example: Decimal odds of 2.50

1. 1 ÷ 2.50 = 0.40
2. 0.40 × 100 = 40.0%

This means the odds suggest a 40% chance of winning the bet.

Another example: Decimal odds of 1.80

1. 1 ÷ 1.80 = 0.556
2. 0.556 × 100 = 55.6%

Shorter odds always imply a higher probability, while longer odds imply a lower probability.

Why this matters: Implied probability allows you to judge whether odds are fair or overpriced, regardless of how they are displayed. When betting with crypto sportsbooks, where markets can move quickly, converting odds to probability helps you spot value before prices shift.

Converting Decimal Odds to American Odds

American (US) odds are displayed as either positive (+) or negative (–) numbers. Which one you use depends entirely on whether the decimal odds are above or below 2.00.

Decimal odds of 2.00 represent an even-money bet. Everything else branches from there.

Decimal Odds Above 2.00 (Positive US Odds)

If the decimal odds are greater than 2.00, the American odds will be positive. Positive US odds indicate the potential profit you would earn on a $100 stake.

Formula: American odds = (decimal odds − 1) × 100

Example: Decimal odds of 3.00

1. (3.00 − 1) × 100
2. 2.00 × 100 = +200

This means a $100 stake would return $200 in profit (plus your original $100 stake).

Another example: Decimal odds of 2.50

1. (2.50 − 1) × 100
2. 1.50 × 100 = +150

Decimal Odds Below 2.00 (Negative US Odds)

If the decimal odds are below 2.00, the American odds will be negative. Negative US odds show how much you need to stake to win $100 in profit.

Formula: American odds = −100 ÷ (decimal odds − 1)

Example: Decimal odds of 1.67

1. −100 ÷ (1.67 − 1)
2. −100 ÷ 0.67 ≈ −150

This means you must stake $150 to win $100 in profit.

Another example: Decimal odds of 1.50

1. −100 ÷ (1.50 − 1)
2. −100 ÷ 0.50 = −200

Why Implied Probability Matters in Crypto Betting

Odds formats may look different, but they all translate to the same thing: implied probability. Understanding probability enables you to compare prices objectively, without being influenced by how attractive or familiar an odds format appears.

This matters even more when betting with crypto sportsbooks.

Crypto betting markets often:

• Move faster than traditional sportsbooks
• React quickly to sharp money
• Offer wider price ranges in niche or volatile markets

In these conditions, odds alone can be misleading. Converting odds into implied probability allows you to see what the bookmaker believes the true chance of an outcome is and whether that estimate makes sense.

For example, decimal odds of 2.20 imply a probability of 45.5%. If your own assessment suggests the outcome wins closer to 50% of the time, the odds may represent value, regardless of whether they are shown as fractional, decimal, or US odds.

Implied probability also makes it easier to:

• Compare the same market across multiple crypto sportsbooks
• Spot pricing errors before odds adjust
• Avoid overvaluing longshots or underestimating short-priced favourites

At its core, profitable betting is not about predicting winners; it’s about identifying mispriced probabilities.

Common Odds Conversion Mistakes to Avoid

Even experienced bettors make errors when converting odds, especially when switching between formats quickly. These mistakes often result from a misunderstanding of what each odds format actually represents.

One of the most common errors is forgetting that decimal odds include the stake. Decimal odds display the total return, not the profit. A decimal price of 2.00 does not mean you will double your money in profit; it means you will receive twice your stake back, including the original wager.

Another frequent mistake is misreading positive and negative American odds. Positive US odds show how much profit you would make on a $100 stake, while negative odds show how much you need to stake to win $100. Mixing these up leads to incorrect assumptions about risk and return.

Bettors also tend to assume short odds are always “safe”. Extremely short prices, such as 1/10 or –1000, imply a very high probability, but they still carry risk. Converting these odds to implied probability highlights just how much you are risking for a small potential return.

Finally, many people try to memorise too many formulas. This usually leads to confusion. The most reliable approach is to convert everything to decimal odds first and then convert them into your preferred format. This single reference point eliminates unnecessary complexity.

Avoiding these mistakes makes odds conversion faster, more accurate, and far less prone to error.

Do Crypto Sportsbooks Use Different Odds Formats?

Crypto sportsbooks do not employ a different odds system, but they often present odds in a more flexible manner than traditional betting sites. Decimal odds are the most common format across crypto betting platforms, though many also allow you to switch between fractional and American odds in the settings.

The underlying prices are the same regardless of format. A market priced at 2.50 in decimal odds represents the same implied probability as 3/2 fractional odds or +150 US odds. The difference is purely how the information is displayed.

Where crypto sportsbooks can differ is in pricing range and volatility. You are more likely to see:

• Extremely short odds on heavy favourites
• Very long odds on futures, novelty, or low-liquidity markets
• Faster odds movement in response to sharp action

This is why a comprehensive odds conversion table, including extreme values, is handy for crypto bettors. Being able to convert any price into implied probability helps you stay grounded when odds shift quickly or look unusually generous.

Ultimately, learning to convert odds manually ensures you are never dependent on a specific display format or tool. Whether you are betting with fiat or crypto, understanding odds and probability puts you in control of every wager.