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Standard Error Calculator

Find the standard error of the mean of a sample, with the sample standard deviation and steps.

Change the values and press Calculate to work out your own figures.

Enter a sample of numbers.

About numbersValues separated by commas, spaces or new lines, for example 10, 2, 38, 23.
Result
Standard error of the mean
4.34967158038
Sample standard deviation (s)
12.3027290817
Count
8
Sum
178
Mean
22.25

The standard error of the mean is 4.34967158038.

Show the working
  1. s = √(Σ(x − mean)² ÷ (n − 1)) = 12.3027290817
  2. SE = s ÷ √n = 12.3027290817 ÷ √8 = 4.34967158038

How to use it

Enter a sample of numbers.

Paste or type the numbers separated by commas, spaces or new lines. Results are worked out exactly and shown to 12 significant figures; Show the working lists each step.

Key facts

SE = s ÷ √n

What the standard error measures

It estimates how much the sample mean would vary from sample to sample. It shrinks as the sample grows: four times the data halves the standard error.

Questions

How do I calculate the standard error?

Divide the sample standard deviation by the square root of the sample size.

Standard error or standard deviation?

SD describes the data; SE describes how precisely the mean is estimated.

Formulas

SE = s ÷ √n

Sources

Limitations

  • Up to 5,000 values. Values are separated by commas, spaces or new lines, so write 1250 rather than 1,250.

Formula version 0.1.0Reviewed