Coding Reliability (Qualitative) Calculator

Work out coding reliability (qualitative) instantly with clear inputs, formula shown and shareable results.

About Coding Reliability (Qualitative) Calculator

Percent agreement between coders always flatters, because agreement happens by chance too. With six equally likely categories, chance agreement is 16.7%, so 84% raw agreement corrects to a kappa of 0.808 - strong. Qualitative research conventionally requires kappa above 0.80 for published coding and 0.67 for exploratory work.

Formulas

Percent agreement

po = agreed decisions / total decisions

Chance-corrected kappa

kappa = (po - pe) / (1 - pe), with pe = 1 / categories

Worked example

With the default values below, Coding Reliability (Qualitative) Calculator returns Percent Agreement of 84.00%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Coding decisions both coders agreed onminimum 0: 168
Total coding decisionsminimum 1: 200
Number of code categoriesminimum 2: 6

Results

Percent Agreement: 84.00%
Chance-Corrected Kappa: 0.8080
Agreement Expected By Chance: 16.67%
Reliability Assessment: Strong reliability - suitable for publication

Step by step

1Values used
2Percent agreement
3Chance-corrected kappa
4Percent Agreement= 84.00
5Chance-Corrected Kappa= 0.8080
6Agreement Expected By Chance= 16.67
7Reliability Assessment= Strong reliability - suitable for publication

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why correct for chance?

Because two coders assigning codes at random would still agree sometimes. With two categories chance agreement is 50%, so raw agreement is nearly meaningless.

Should both coders code everything?

Commonly 10-25% of the material is double-coded to establish reliability, then one coder completes the rest once agreement is demonstrated.