F.TEST Function in Excel: Are Two Spreads Different?

F.TEST Function in Excel: Are Two Spreads Different? featured illustration

📎 This article includes 1 downloadable practice file ↓

⏱ 2 min readUpdated 5 October 2026

StatisticsLevel: ExpertAvailable in: Excel 2010+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. F.TEST in practice
  5. Where you will use it
  6. Worked example
  7. Mistakes people make
  8. Related functions
  9. Continue learning

F.TEST checks whether two samples have different variances — for instance, before choosing T.TEST type 2 or 3.

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Syntax

=F.TEST(array1, array2)
Argument What it means
array1, array2 Two samples.

Examples

Example 1

=F.TEST(B2:B31, C2:C31)

Low p-value → use T.TEST type 3 (unequal variance).

F.TEST in practice

Where you will use it

  • Are two machines equally consistent?
  • Compare variance of two suppliers
  • Pre-check before a t-test

Worked example

CaseComparisonFormulaResult
1Similar spread=ROUND(F.TEST(INDEX($H$1:$M$3,A2,0),INDEX($O$1:$T$3,A2,0)),4)0.5276
2Very different spread=ROUND(F.TEST(INDEX($H$1:$M$3,A3,0),INDEX($O$1:$T$3,A3,0)),4)0
3Identical=ROUND(F.TEST(INDEX($H$1:$M$3,A4,0),INDEX($O$1:$T$3,A4,0)),4)1

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
Reading the resultIt's a p-value; small means the spreads differ
Tiny samplesUnreliable below ~10 points each

T.TEST · VAR.S

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📎 Practice files for this article

  • 📗
    Practice workbook: Statistics advanced33 tasks on realistic sales data — type your formula, the Check column turns green when it is right. Answers sheet included.
    ⬇ XLSX · 36 KB

Free to use for learning. Files with macros (.bas) are plain text — import them with Alt+F11 → File → Import File, and always test on a copy.

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