Standard Deviation Calculator

Our Standard Deviation Calculator is an online tool to calculate the standard deviation for your given data set. With this calculator, you can easily calculate the standard deviation for the population or sample data. Simply input your values into the calculator and let it do the calculations for you. Understanding the standard deviation can help you better analyze your data and draw accurate conclusions. Use our Standard Deviation Calculator today to get your results in just a few seconds.

Explore other calculators or unit converters or try out our Standard Deviation Calculator and learn more about Standard Deviation .

Solution:
Solution will be shown here.

Standard Deviation Calculator Details


SchoolMyKids provides a Standard Deviation Calculator to help you quickly and accurately measure how spread out your data is. This tool is designed for students, parents, and professionals who want to understand the variability in their data sets with ease. 

What is a Standard Deviation Calculator?

A Standard Deviation Calculator is a tool that calculates how much the numbers in your data set differ from the average (mean). Standard deviation shows whether your data points are close to the mean or widely spread out. It is used in many fields, including science, business, and education, to understand the consistency or diversity of data. 

Understanding Key Terms

  • Data Set: The group of numbers you want to analyze. 
  • Mean (Average): The sum of all numbers divided by the count of numbers. 
  • Standard Deviation: A measure of how spread out the numbers are from the mean. 
  • Sample: A part of the whole group (population) you are studying. 
  • Population: The entire group of interest. 
  • n: The number of values in your data set. 

How to Use the Standard Deviation Calculator

You can use the calculator in two ways: 

  • Sample Standard Deviation: Use this if your data is a sample from a larger group. 
  • Population Standard Deviation: Use this if your data includes every member of the group. 

Steps: 

  • Choose whether you want to calculate the sample or population standard deviation. 
  • Enter your numbers, separated by commas. 
  • Click “Calculate” to see the standard deviation. 

Understanding Your Results

  • A low standard deviation means your numbers are close to the mean (less spread out). 
  • A high standard deviation means your numbers are more spread out from the mean. 
  • The calculator will show the standard deviation value and whether it is for a sample or a population. 

How Do I Calculate Standard Deviation? (Example)

Sample Standard Deviation Formula 

xi: Each number in your data set 

x̄: Mean of your data set 

n: Number of values 

Population Standard Deviation Formula 

μ: Mean of the population 

Example 

Suppose your data set is: 4, 8, 6, 5, 3 

Step 1: Find the mean 

x̄ = (4+8+6+5+3)/5 = 5.2 

Step 2: Find the squared differences from the mean 

(4 - 5.2)² = 1.44 

(8 - 5.2)² = 7.84 

(6 - 5.2)² = 0.64 

(5 - 5.2)² = 0.04 

(3 - 5.2)² = 4.84 

Sum: 1.44 + 7.84 + 0.64 + 0.04 + 4.84 = 14.8 

Step 3: Calculate standard deviation 

Sample: 1.92354 

Population: 1.72047 

Common FAQs

When should I use sample standard deviation instead of population standard deviation?

Use the sample standard deviation if your data is just a part of the whole group. Use the population standard deviation if you have data for the entire group. 

Can I enter negative numbers or decimals?

Yes, you can enter any real numbers. 

What does a SD of zero mean?

It means all your numbers are exactly the same—there is no spread in your data. 

SMK's Standard Deviation Calculator is a helpful tool for understanding how much your data values differ from the average.