Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Confidence Interval Calculator

Compute the margin of error around a sample mean for a 90%, 95%, or 99% confidence interval using the z-distribution. The half-width of the CI tells you how precisely your sample estimates the population mean — essential for survey reporting, scientific publication, and any inference.

Sample Size (n)

Standard Deviation

Confidence Level

Fill in the required fields to see your result.

Statistics

Standard Error Calculator

Compute the standard error of the mean (SEM) from the sample standard deviation and sample size, SEM = s/√n. Quantifies how precisely a sample mean estimates the underlying population mean — the foundation of confidence intervals, t-tests, and any inferential statistic.

Standard Deviation

Sample Size

Fill in the required fields to see your result.

Key differences

	Confidence Interval Calculator	Standard Error Calculator
Category	Statistics	Statistics
Inputs required	3	2
Result	Margin of Error (±)	Standard Error
What it does	Compute the margin of error around a sample mean for a 90%, 95%, or 99% confidence interval using the z-distribution. The half-width of the CI tells you how precisely your sample estimates the population mean — essential for survey reporting, scientific publication, and any inference.	Compute the standard error of the mean (SEM) from the sample standard deviation and sample size, SEM = s/√n. Quantifies how precisely a sample mean estimates the underlying population mean — the foundation of confidence intervals, t-tests, and any inferential statistic.