Confidence Interval Calculator
Confidence interval calculator: confidence interval for a mean from the sample mean, standard deviation and sample size, using the t-distribution.
x̄ ± t · s√n
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
CI = x̄ ± t × s/√n. With small samples the t value is larger than z (2.064 instead of 1.96 for n = 25 at 95 %).
Frequently asked questions
Mean 72, s = 8, n = 25, 95 %?
68.70 to 75.30 (± 3.30).
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