Statistics

Welch t-Test Calculator

Calculate Welch’s two-sample t statistic and approximate degrees of freedom without assuming equal variances.

Statistics

Move between weighted summaries, t statistics, chi-square goodness-of-fit and one-way ANOVA calculations.

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Calculate Welch’s two-sample t statistic and approximate degrees of freedom without assuming equal variances.

How it works

Enter compatible statistical values. The calculator validates the inputs and applies t = (x̄₁−x̄₂) / √(s₁²/n₁ + s₂²/n₂), with Welch-Satterthwaite degrees of freedom.

The formula

t = (x̄₁−x̄₂) / √(s₁²/n₁ + s₂²/n₂), with Welch-Satterthwaite degrees of freedom

Variables: x̄₁ = Mean 1; s₁ = Standard deviation 1; n₁ = Sample size 1; x̄₂ = Mean 2; s₂ = Standard deviation 2; n₂ = Sample size 2.

Worked example

Example: Means 100 and 94 with standard deviations 10 and 12 and sample sizes 25 and 30 give t≈2.0226.

Frequently asked questions

What is this Statistics calculator intended for?

It is an educational tool for descriptive and inferential statistical calculations from supplied values or summary statistics.

Does this calculator make a complete statistical decision?

No. Where a test statistic is calculated, the tool does not automatically replace study design, assumption checks, p-value interpretation, confidence intervals or subject-matter judgment.

Last content reviewSeptember 26, 2026
Editorial reviewHe-Sab Editorial Review

Sources and references

These sources are used to verify terminology, formulas, and information related to this calculator.