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FTEST Function

Excel 2007+, Excel 2010, Excel 2013, Excel 2016

Summary

The Excel FTEST function performs an F-test to compare variances between two data sets, returning the two-tailed probability that their variances are significantly different. This statistical tool helps determine if two samples exhibit different levels of variability.

Syntax

FTEST(array1, array2)

Parameters

Parameter	Type	Required	Description
array1	`Array/Range`	Yes	The first array or range of numeric data for variance comparison
array2	`Array/Range`	Yes	The second array or range of numeric data for variance comparison

Using the FTEST Function

FTEST calculates the probability that two datasets have different variances using the F-test statistic. This is valuable in statistical analysis to assess whether variability in one dataset significantly differs from another, such as comparing test score dispersion between different groups.

Common FTEST Examples

Basic FTEST Example

=FTEST(A2:A6,B2:B6)

Tests variance difference between two datasets containing values like 20,31,38,40 and 28,15,21. Returns approximately 0.6483 indicating variances are not significantly different.

Test Score Comparison

=FTEST(C2:C10,D2:D10)

Compares variability in test scores between public school (C2:C10) and private school (D2:D10) datasets.

Frequently Asked Questions

A low probability (close to 0) suggests the variances are significantly different. Higher values (close to 1) indicate similar variances.

FTEST is the legacy function; F.TEST is the modern replacement with improved accuracy. Both perform the same F-test.

Common Errors and Solutions

#DIV/0!

Cause: Dataset has fewer than 2 points or zero variance

Solution: Ensure both arrays have at least 2 numeric values with non-zero variance

#VALUE!

Cause: Arrays contain non-numeric data that can't be ignored

Solution: Verify data contains only numbers, text/logical values are ignored

Notes

Replaced by F.TEST function for better accuracy
Ignores text, logical values, empty cells but includes zeros
LINEST returns F statistic; FTEST returns probability
Requires minimum 2 data points per array

Compatibility

Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Microsoft 365

Not available in: Excel 2003 and earlier

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+, Excel 2010, Excel 2013, Excel 2016