Enter the frequency of the first phenotype and the frequency of the smallest phenotype into the Phenotypic Ratio Calculator. The calculator will evaluate and display the Phenotypic Ratio.

## Phenotypic Ratio Formula

The following formula is used to calculate the Phenotypic Ratio.

PHR = F1 / FS
• Where PHF is the Phenotypic Ratio ( )
• F1 is the frequency of the first phenotype
• FS is the frequency of the smallest phenotype

To calculate the phenotypic ratio, divide the frequency of the first phenotype by the frequency of the smallest phenotype.

## How to Calculate Phenotypic Ratio?

The following example problems outline how to calculate Phenotypic Ratio.

Example Problem #1:

1. First, determine the frequency of the first phenotype.
• The frequency of the first phenotype is given as: 15.
2. Next, determine the frequency of the smallest phenotype.
• The frequency of the smallest phenotype is provided as: 5.
3. Finally, calculate the Phenotypic Ratio using the equation above:

PHR = F1 / FS

The values given above are inserted into the equation below and the solution is calculated:

PHR = 15 / 5 = 3 ( )

Example Problem #2:

For this problem, the variables required are provided below:

frequency of the first phenotype = 16

frequency of the smallest phenotype = 6