Welch's t-test Calculator
Compute Welch t statistic and degrees of freedom from two groups.
Input Data
Input Group1 mean x̄₁.
Input Group2 mean x̄₂.
Input Group1 SD s₁.
Input Group1 n₁.
Input Group2 SD s₂.
Input Group2 n₂.
Results
3.421596
55.3337
Welch t with Satterthwaite df.
At a glance:Welch's t-test Calculator: enter parameters to compute results; complements related calculators.
Formula
t = (x̄₁−x̄₂) / √(s₁²/n₁ + s₂²/n₂).
df = (a+b)² / (a²/(n₁−1) + b²/(n₂−1)), a = s₁²/n₁, b = s₂²/n₂.
How to Use
- Enter both groups' means, SD and sizes.
- It returns t and df.
Case Studies
x̄₁=10,x̄₂=8,s₁=2,s₂=2.5,n=30 → t≈3.4221, df≈55.33
se = √(4/30 + 6.25/30) ≈ 0.5845, t ≈ 3.4221.
FAQ
Welch vs Student t-test?
Welch relaxes the equal-variance assumption and is generally recommended by default.
Related Tools
References
Content review: Calculatorism Science Team. Formula and numeric tests verified; results for reference only.