Variance and Standard Deviation Calculator

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This standard deviation calculator calculates the sample standard deviation and variance from a data set. This isn’t your ordinary variance and standard deviation calculator. Type in your numbers and you’ll be given: the variance, the standard deviation, plus you’ll also be able to see your answer step-by-step below.

Watch this short video for instructions, or scroll down to use the calculator:

Data set:


  • Variance:
  • Standard Deviation:

  1. First, I added up all of the numbers:
  2. I squared the total, and then divided the number of items in the data set
  3. I took my set of original numbers from step 1, squared them individually this time, and added them all up:
  4. I subtracted the amount in step 2 from the amount in step 3:
  5. I subtracted 1 from the number of items in my data set:
  6. I divided the number in step 4 by the number in step 5:
  7. Finally, I took the square root of the number from step 6 (the Variance),

variance and standard deviation calculator
Standard deviations are a unit of measurement; they measure how spread out your data is around the mean. The bulk of data (68%) lies within one standard deviation from the mean.

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