# z score in Excel

The z-score, also known as a standard score, is used in statistics. It measures the number of standard deviations of a specific number.

To calculate z-score you can use the following formula.

z-score = (x – μ) / σ

x – value

μ – mean

σ – standard deviation

Let’s take a look at the following example. This site iqtestprep.com shows the IQ score for famous people.

I chose just a few examples to illustrate how you can calculate mean, standard deviation, and the z-score. You can copy the following example.

 First Name Last Name IQ Muhammad Ali 78 Rowan Atkinson 178 Kobe Bryant 114 Warren Buffet 145 Miley Cyrus 120 David Duchovny 147 Thomas Edison 145 Jodie Foster 132 Ariana Grande 105 Stephen Hawking 160 Charles Manson 109 OJ Simpson 89

## Calculating standard deviation in Excel

1. Calculate the mean for the IQ scores, by using the following formula =AVERAGE(C2:C13) and call it mean. 1. Calculate standard deviation with this formula: =STDEVPA(C2:C13) and call it stdev.
2. In cell D2, calculate the z-score for the first IQ: =STANDARDIZE(C2, mean, stdev).
3. Use autofill to calculate the remaining z-scores.

This is the result of our calculations. 