Intraclass Correlation (ICC) Calculator

Measure how consistently raters score the same subjects. Paste one row per subject with each rater’s numeric score.

One row per subject. Each column is a rater giving a numeric score.
ICC(2,1) single measures
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Single vs average measures

Single-measures ICC estimates the reliability of one rater’s score, which is what you want when a single rater will score each subject in practice. Average-measures ICC estimates the reliability of the mean of all raters, which applies when you will always average several raters together. This tool reports both.

Which form this uses

This calculator computes the two-way random-effects, absolute-agreement form, ICC(2,1) and ICC(2,k), the version usually reported for inter-rater reliability. Common interpretation bands are: below 0.5 poor, 0.5 to 0.75 moderate, 0.75 to 0.9 good and above 0.9 excellent.

Frequently asked questions

How is ICC different from Cohen’s kappa?

Kappa is for categorical ratings, where raters pick a category. ICC is for numeric ratings on a continuous scale, and it credits partial agreement between close scores rather than treating any mismatch as full disagreement.

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