关于本计算器
Sample size from margin of error, standard deviation and confidence level via n = (zσ/E)².
样本量计算器
达到误差范围所需样本数。
输入计算参数
计算结果摘要
所需样本量97people
z-value1.96
(zσ/E)²96.04
常见问题
Halve the margin?
Quadruple the sample — size scales with the square of precision.
Unknown σ?
Pilot data or range/4 estimates work; conservative 0.5 suits proportions.
Rounded up?
Always round up: 96.2 people means surveying 97.