Calculator
Enter the values below. Every quantity identifies its unit or meaning.
%
observations
%
Formula / method
CI ≈ p̂ ± z√[p̂(1−p̂)/n].
CI ≈ p̂ ± z√[p̂(1−p̂)/n].
How to use this calculator
What to enter
Enter or select the following as requested: Observed proportion; Sample size; Confidence level. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The numerical result follows the operation or relationship named by the calculator and the values entered. Check the order of operations, sign, precision, and units shown, especially when combining percentages or ratios.
When to use it
Use this to calculate or verify a numerical value. Recheck the input values and rounding if the result will be used in a report, measurement, or further calculation.