Z Score Calculator

Z score calculator finds the z-score for any raw value of X. Our z value calculator tells you how many standard deviations away from the mean value where x lies. Just enter the raw score, mean value, and standard deviation and get instant results. 

What Is Z Score?

Z Score is the distance between the mean score and the experimental data point. In statistical data analysis, it is also known as the standard score, z value, normal score, and standardized score. 

Z Score Formula: 

Z value is the dimensionless quantity that is used to indicate the signs and fractions, and the number of standard deviations by which the mean value is measured.

To find the z-score by z score calculator or by manually, just you need to apply the following z score equation:

z = (x-μ) / σ

Where;

• x = raw score 
• μ = population mean
• σ = population standard deviation

As the formula shows, the z-score is simply the raw score minus the population mean, divided by the population standard deviation. 

Mean is the sum of all data set divided by the number of the data point. You can also try our mean calculator to find out the mean. 

How To Calculate Z Score? 

Our innovative z chart calculator aims to simplify and streamline the z-score for any raw value of X. You need to look at the example to clarify how to find z scores with the help of z score calculator or manually. 

Example:

The dataset has a mean of 4 and a standard deviation of 2. What is the zscore of a data set of 8 numbers?

Solution:

Given Data:

x = 8

Mean (μ) = 4

Standard deviation (σ) = 2

The formula of Z is:

Z = (X − μ) / σ

Put the Values in z score equation

Z = (8 - 4) / 2

Z = 4 / 2

Z = 2

You can find out the value of (μ) with the help of our average calculator.

Working Of Z Score Calculator: 

Our z calculator determines the z scores for the raw data and shows proper and fast calculations. You only need to perform the following steps to calculate z score via this tool:

Input:

• Put the value of the data point (x)
• Put the value of the data mean μ
• Put the value of standard deviation σ
• Tap “calculate”

Output:

Our online z-score calculator reports the following outputs as a result of the inputs. 

• Z scores value 
• Step-by-step solution

FAQs:

How Do You Calculate Z-score For Age?

The formula for calculating the z-score according to the formula z-score = (X-m)/SD, in which X is the observed value (height, weight, or BMI), and m and SD are the mean and standard deviation values of the distribution corresponding to the reference population.

What Is The Difference Between the Z-score And Standard Deviation?

Z score indicates how much a given value varies from the standard deviation. If the standard deviation is unknown, the z-score can be calculated using the sample mean, x̄ (pronounced x bar), and sample standard deviation, as estimations of the population values.

Is The T Value The Same As The Z-score?

Z score is the standardization from the population raw data or more than 30 sample data to a standard score, while the T score is the standardization from the sample data of less than 30 data to a standard score. Z score ranges from -3 to 3, while the T score ranges from 20 to 80.

What Is a Normal Z-score For a 70-Year-Old Woman?

It is recommended that women < 70 years old are treated if the bone mineral density T-score is below -2.5. For women > or = 70 years of age, a lower cut-off point has been chosen, i.e. a Z-score below -1.

Z Score Table: 

The z-score table is used to determine the percentage of the population that lies above or below any z-value. Simply, calculate the z score chart from this z score calculator and find where the z table chart values lie.

Z Table (Right):

Z Table (Left):

References:

From the source Wikipedia: Standard score, Calculation, Applications, Standardized in mathematical statistics, T-score. 

From the source Khan Academy: What are z-scores, Z-scores review, comparing with the z score, calculating z score.