Cronbach's Alpha Calculator
Measure internal consistency reliability of a scale or questionnaire
Enter data with participants as rows (;) and items as columns (,)
About Cronbach's Alpha
Cronbach's alpha measures internal consistency - how closely related a set of items are as a group.
Formula: α = (k/(k-1)) × (1 - Σσ²ᵢ/σ²ₜ)
Interpretation (George & Mallery):
- α ≥ 0.9: Excellent
- 0.8 ≤ α < 0.9: Good
- 0.7 ≤ α < 0.8: Acceptable
- 0.6 ≤ α < 0.7: Questionable
- 0.5 ≤ α < 0.6: Poor
- α < 0.5: Unacceptable