PHI
The PHI function returns the cumulative distribution function of a standard normal distribution. It calculates the probability that a random variable is less than or equal to a specified value in a normal distribution with a mean of 0 and a standard deviation of 1. This function is often used in statistical analysis to determine the probability of a certain event occurring based on a normal distribution. How to use
PHI
formula?  Examples of using
PHI
formula PHI
formula not working? Similar formulas to
PHI
Usage
Use the PHI
formula with the syntax shown below, it has 1 required parameter:
 x (required):
The value at which to evaluate the cumulative distribution function.
Examples
Here are a few example use cases that explain how to use thePHI
formula in Google Sheets.
Calculating the probability of a value in a normal distribution
By using the PHI function, you can calculate the probability that a random variable is less than or equal to a specified value in a normal distribution with a mean of 0 and a standard deviation of 1.
Hypothesis testing
The PHI function is commonly used in hypothesis testing to determine the probability of observing a test statistic as extreme as the one calculated from a sample, assuming that the null hypothesis is true.
Calculating zscores
The PHI function can be used to calculate zscores, which are a measure of how many standard deviations a data point is from the mean of a normal distribution.
Common Mistakes
PHI
not working? Here are some common mistakes people make when using the PHI
Google Sheets Formula:
Forgetting to convert the value to a zscore
The PHI
function is used to calculate the cumulative distribution function of the standard normal distribution, so it expects a zscore as input. If you have a value that is not in zscore form, you need to convert it to a zscore before using the PHI
function.
Using the wrong sign for the input
The PHI
function expects a zscore as input. It is important to use the correct sign for the input value, as this affects whether you are calculating the probability of being less than or greater than the value. For example, if you want to calculate the probability of being less than a certain value, you need to use a negative zscore as input.
Related Formulas
The following functions are similar to PHI
or are often used with it in a formula:

NORMDIST
The
NORMDIST
function in Google Sheets calculates the normal distribution for a specified value, mean, and standard deviation. It returns the probability of a value occurring within a specified range of a normal distribution. It is commonly used in statistics, finance, and science to analyze data and make predictions. 
NORMINV
The
NORMINV
function returns the inverse of the normal cumulative distribution for a specified value, mean, and standard deviation. It is commonly used in statistics to find the value at which a given percentage of observations lie below that value. 
NORMSDIST
The
NORMSDIST
function returns the area under a normal distribution curve to the left of a specified value. This function is commonly used in statistics to calculate probabilities. 
NORMSINV
The
NORMSINV
function calculates the inverse of the standard normal cumulative distribution for a specified value of x. It is commonly used in statistical analysis to transform data from a normal distribution to a standard normal distribution with a mean of 0 and a standard deviation of 1.
Learn More
You can learn more about the PHI
Google Sheets function on Google Support.