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Confidence Interval Calculator for Means

This calculator is used to find the confidence interval (or accuracy) of a mean given a survey’s sample size, mean and standard deviation, for a chosen confidence level.

How To Interpret The Results

For example, suppose you carried out a survey with 200 respondents. If you had a mean score of 5.83, a standard deviation of 0.86, and a desired confidence level of 95%, the corresponding confidence interval would be ± 0.12. That is to say that you can be 95% certain that the true population mean falls within the range of 5.71 to 5.95.

Calculator

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Sample Size

The number of respondents who answered the question.

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Observed Mean

The mean average score for the question you are interested in.

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Observed Standard Deviation

The standard deviation of the mean average score.

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Confidence Level

The degree of confidence in whether or not the true figure for the population lies within the confidence interval for the survey.

For example, a 95% confidence level indicates there is a 1 in 20 (5%) chance that the true population result falls outside the confidence interval range.

Results

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