🧮AlphaCalc

Confidence Interval Calculator

Calculate a confidence interval for a sample mean at 80–99% confidence levels.

95% Confidence Interval

94.6323 to 105.3677

Margin of error: ± 5.3677

So funktioniert's

Margin of error = z-score × (standard deviation / √sample size), added and subtracted from the sample mean.

Which confidence level should I use?

95% is the most common default in research and reporting; higher levels (98%, 99%) give a wider, more conservative interval.