How to use the heterogeneity i2 calculator
Prepare the values for this calculation
Calculate Cochran Q and I² heterogeneity from study effects and standard errors. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.
Enter and check each input
- Study effect, standard error — one study per line: keep one record per line and preserve the column order shown in the example. Replace the example data with your own complete dataset.
The input table gives a complete example. Keep units and time periods consistent across related fields.
Calculate and resolve any input error
Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.
Interpret the answer
Check I² heterogeneity first. With the unchanged example inputs, it is 0%. Compare the additional metrics with the primary result; each has its own label and unit.
Compare and keep a useful result
The result diagram shows the inputs, method and output. A numeric chart is shown only when the calculation supports a meaningful numeric relationship.
Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.
Heterogeneity I2 Calculator formula
Q=Σwᵢ(yᵢ−ȳw)²; I²=max(0,(Q−df)/Q)×100%, df=k−1.
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Study effect, standard error — one study per line | One row per line | 0.20,0.10
0.35,0.15
0.10,0.12
0.40,0.20 |
Worked example
Using the example inputs above, the i² heterogeneity is 0%.
- I² heterogeneity
- 0%
- Cochran Q
- 2.6010981912
- df
- 3
- Fixed-effect pooled estimate
- 0.2197674419
Results and assumptions
The output uses the i² heterogeneity convention and formula shown above. Match the entered units and source assumptions when comparing results.
Fix an input or unexpected result
If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.
If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.