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CHISQ.INV Function
Summary
The CHISQ.INV function calculates the inverse of the left-tailed chi-squared distribution, returning the chi-squared value for a given cumulative probability and degrees of freedom. Essential for statistical hypothesis testing and confidence interval calculations.
Syntax
CHISQ.INV(probability, deg_freedom)Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
| probability | Number |
Yes | A probability value between 0 and 1 (exclusive) for the chi-squared distribution |
| deg_freedom | Integer |
Yes | Number of degrees of freedom, truncated to integer if non-integer |
Using the CHISQ.INV Function
CHISQ.INV is used in statistical analysis to find critical values for chi-squared tests. It converts a probability (alpha level) into the corresponding chi-squared statistic value, which is crucial for determining test rejection regions and constructing confidence intervals for variance estimates.
Common CHISQ.INV Examples
Basic Critical Value Calculation
=CHISQ.INV(0.93,1)Returns 3.283 for 93% cumulative probability with 1 degree of freedom (matches Microsoft example)
Two Degrees of Freedom Example
=CHISQ.INV(0.6,2)Returns 1.833 for 60% cumulative probability with 2 degrees of freedom
Hypothesis Testing Alpha=0.05
=CHISQ.INV(0.95,10)Finds critical chi-squared value for 5% significance level with 10 degrees of freedom
Real Dataset Application
=CHISQ.INV(0.975,5)Calculates upper critical value for 95% confidence interval with 5 degrees of freedom
Frequently Asked Questions
Common Errors and Solutions
#VALUE!
Cause: Non-numeric input for probability or deg_freedom
Solution: Ensure both arguments are valid numbers
#NUM!
Cause: Probability <0 or >1, or deg_freedom <1 or >10^10
Solution: Use probability between 0 and 1 (exclusive), deg_freedom ≥1
#NUM!
Cause: Deg_freedom exceeds Excel's maximum (10^10)
Solution: Reduce degrees of freedom or use approximation
Notes
- If deg_freedom is non-integer, Excel automatically truncates it
- Maximum deg_freedom supported: 10^10
- If probability = 0, may return 0 depending on degrees of freedom
- Critical for chi-squared goodness-of-fit tests, independence tests, and variance analysis
Compatibility
Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Excel 365
Not available in: Excel 2003 and earlier
Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+