Sample Size Calculator
Estimate the required sample size for statistical studies and surveys.
Required Sample Size: —
Uses the standard normal (Z) approximation.
Example
Standard deviation = 15
Margin of error = 3
Confidence level = 95%
→ Required sample size ≈ 96
Margin of error = 3
Confidence level = 95%
→ Required sample size ≈ 96
What is sample size?
Sample size represents the number of observations required to estimate a population parameter with a desired level of accuracy.
Why is sample size important?
Choosing an appropriate sample size ensures reliable results while avoiding unnecessary data collection.
Frequently Asked Questions
What happens if the sample size is too small?
Small samples lead to higher uncertainty and wider confidence intervals.
Does higher confidence require a larger sample?
Yes. Higher confidence levels require larger sample sizes.