Cronbach's Alpha Calculator
Estimate raw Cronbach alpha from complete item response data with alpha if item deleted.
At a glance
- Computes
- Raw Cronbach's alpha, item-total statistics, and alpha if each item is deleted.
- You supply
- Complete item response data, one row per respondent, one column per item.
- Use when
- You need the internal consistency of a multi-item scale scored in one direction.
- Not for
- Agreement between two raters on the same subjects. Cohen's Kappa Calculator
Value by category; reference at Overall alpha
Cronbach's alpha
Enter data
Rows are respondents, columns are items.
| Metric | Value |
|---|
| Item | Variance | Alpha if deleted |
|---|
alpha = k/(k - 1) * (1 - sum(item variances) / total score variance)
How?
How this is calculated
This calculator uses raw Cronbach's alpha from complete numeric item responses. Item variances and total score variance use sample variance. Alpha if item deleted repeats the same formula after removing one item.
Formula: alpha = k/(k - 1) * (1 - sum(item variances) / total score variance)
Sources
- R psych alpha. R Documentation. Retrieved .
- Cronbach alpha overview. Wikipedia. Retrieved .
Method last reviewed