t-Statistic Calculator

Compute the one-sample t-statistic, degrees of freedom, standard error, and p-value from x̄, μ₀, sample SD, and n.

Frequently Asked Questions

What is the t-statistic?

A standardized measure of how far the sample mean is from a hypothesized value, in units of standard error: t = (x̄ - μ₀) / (s/√n).

What are degrees of freedom?

For a one-sample t-test, df = n − 1. Lower df means heavier-tailed t distribution and more uncertainty about the population SD.

When does the t-test break down?

When the underlying data is strongly non-normal at small n, or when observations aren't independent. With n ≥ 30 the central limit theorem usually rescues it.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.