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Chi-Square Test Calculator

Run goodness-of-fit or independence tests with expected counts, residuals, and Cramer's V.

Input

Configure inputs first. Final results, visuals, downloads, and copy summary remain hidden until Calculate Chi-Square succeeds.

Chi-square methodAlpha

Observed countsExpected countsLeave blank for equal expected counts.

What This Tool Does

The Chi-Square Test Calculator evaluates count data only after Calculate Chi-Square is clicked and warns about approximation assumptions.

Method

The chi-square statistic sums squared observed-minus-expected differences divided by expected counts.

Worked Example

Observed counts 20, 30, 50 with equal expected proportions are compared against expected counts of 33.33 each.

Common Mistakes

Using percentages instead of counts.
Interpreting association as causation.

Limitations

Small expected counts can make the approximation unreliable.
Exact tests are out of scope.

References

NIST e-Handbook: Quantitative Techniques: NIST/SEMATECH e-Handbook of Statistical Methods, Exploratory Data Analysis quantitative techniques.

Goodness-of-fit versus independence?

Goodness-of-fit compares one count distribution to expected counts; independence evaluates a contingency table.

What is Cramer's V?

It is an effect-size measure for chi-square association.

Does chi-square show causation?

No. It evaluates count association or fit, not causal direction.

What if expected counts are low?

The chi-square approximation may be unreliable; exact methods may be needed.

Does the Chi-Square Test Calculator calculate automatically while I type?

No. Inputs and CSV previews never produce final statistics until the explicit calculate button is clicked.

Are CSV files uploaded?

No. Selected CSV files are processed locally in the browser. ScholarTool does not upload the file to a third-party calculation or data-analysis API.

Can a p-value prove a hypothesis?

No. A p-value is evaluated against the selected alpha level under stated assumptions; it does not prove the null or alternative hypothesis.

Engineering disclaimer

This statistics tool is intended for education, planning, and preliminary analysis. Review assumptions, study design, and professional statistical judgement before using results in research, engineering, safety, regulatory, or compliance decisions. ScholarTool does not prove hypotheses or replace qualified analysis.

Need Professional Support?

ScholarTool is powered by ScholarEase Consultancy Services LLP. Professional engineering, simulation, research, and technical documentation support is available through the connected services website.

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Last reviewed: 2026-07-07

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Engineering disclaimer

Chi-Square Test Calculator

Input

What This Tool Does

Method

Worked Example

Common Mistakes

Limitations

References

Related Tools

Engineering disclaimer

Need Professional Support?

Chi-Square Test Calculator

Input

What This Tool Does

Method

Worked Example

Common Mistakes

Limitations

References

Related Tools

Engineering disclaimer

Need Professional Support?