Use our free Confidence Interval Calculator to quickly determine the range within which the true population mean is likely to fall. Understand your data better by calculating the margin of error, lower bound, and upper bound using your sample mean, standard deviation, and sample size. Ideal for researchers, students, and analysts.
Formula:
Formula for Confidence Interval (for Mean with Z-score Approximation)
Confidence Interval = X̄ ± Z * (s / √n)
- X̄ (Sample Mean): The average value of your sample data.
- Z (Z-score): The critical value corresponding to your chosen confidence level (e.g., 1.96 for 95% confidence). This calculator uses Z-scores, which are appropriate for large sample sizes (n > 30) or when the population standard deviation is known.
- s (Sample Standard Deviation): A measure of the spread or dispersion of your sample data.
- n (Sample Size): The total number of observations in your sample.