A t-test compares a mean with a reference or compares two means while accounting for estimated sampling variability. One-sample, paired, pooled, and Welch variants answer different questions and rely on independence, pairing, approximate normality, and variance assumptions that must match the study design.
T-Test Calculator applies this concept to its defined inputs and workflow. It requires an explicit Calculate T-Test action and never accepts or proves the null hypothesis.
The calculator evaluates manual values and returns t statistic, p-value, and effect size using the stated method. Input structure, labels, missing values, and selected options must match the intended workflow. Users should interpret the output within the assumptions shown on the page and repeat the check with trusted reference values when the result affects engineering or research decisions. Normality and independence assumptions should be reviewed.