User Rating 0.0
Total Usage 0 times
Dec
US
Frac
%

Bet Visualization

Stake: $100
Profit: $100
Total Return: $200.00
Is this tool helpful?

Your feedback helps us improve.

About

This tool eliminates the complexity of switching between international betting formats. Whether you are analyzing markets in Europe (Decimal), the UK (Fractional), or the US (American/Moneyline), understanding the mathematical equivalence is critical for identifying value.

Misinterpreting odds leads to incorrect risk assessment. For instance, a common mistake is conflating 2.00 Decimal odds with 2/1 Fractional odds (the correct equivalent is 1/1). This converter standardizes all formats into a single mathematical truth, allowing you to calculate your Return on Investment (ROI) and Implied Probability without manual formula errors.

We use standard algorithms utilized by major bookmakers, ensuring precision up to two decimal places for standard formats and exact fractional reduction where possible.

odds converter betting calculator american odds decimal odds implied probability

Formulas

1. American to Decimal

For positive American odds (e.g., +150):

D = Odds100 + 1

For negative American odds (e.g., -200):

D = 100|Odds| + 1

2. Decimal to Implied Probability

P% = 1D × 100

Where:
D = Decimal Odds
P = Probability

Reference Data

DecimalAmericanFractionalImp. Probability
1.10-10001/1090.9%
1.20-5001/583.3%
1.50-2001/266.7%
1.91-11010/1152.4%
2.00+1001/150.0%
2.50+1503/240.0%
3.00+2002/133.3%
4.00+3003/125.0%
10.00+9009/110.0%
101.00+10000100/10.99%

Frequently Asked Questions

The sign indicates the payout structure relative to a $100 stake. A minus sign (-) represents the "Favorite", indicating how much you must bet to win $100 (e.g., -150 means bet $150 to win $100). A plus sign (+) represents the "Underdog", indicating how much you win on a $100 bet (e.g., +200 means bet $100 to win $200).
Decimal odds (e.g., 2.50) represent the total return (Stake + Profit). Fractional odds (e.g., 3/2) represent only the Profit relative to the Stake. To convert Decimal to Fractional, subtract 1 from the Decimal value (2.50 - 1 = 1.5 = 3/2).
Implied Probability translates odds into a percentage chance of winning. If your estimated probability of an outcome is higher than the bookmaker's implied probability, you have found "Positive Expected Value" (+EV).
Odds of 1.01 represent a very high probability (99%). In American format, this is -10000. In Fractional, it is 1/100.