SUMSQ Function in Excel: Sum of Squares

SUMSQ Function in Excel: Sum of Squares featured illustration

📎 This article includes 1 downloadable practice file ↓

⏱ 2 min readUpdated 5 October 2026

MathLevel: ExpertAvailable in: Excel 2007+

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

SUMSQ squares each value and adds them up — the building block of error measures such as RMSE.

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Syntax

=SUMSQ(number1, [number2], ...)
Argument What it means
number1… Values or ranges.

Examples

Example 1

=SQRT(SUMSQ(D2:D25)/COUNT(D2:D25))

RMSE when column D holds forecast minus actual.

SUMSQ in practice

Where you will use it

  • Sum of squares for variance
  • Error totals
  • Distance calculations

Worked example

ValuesFormulaResult
3, 4=SUMSQ(CHOOSE(ROW()-1,{3,4},{1,2,3},{10}))25
1, 2, 3=SUMSQ(CHOOSE(ROW()-1,{3,4},{1,2,3},{10}))14
10=SUMSQ(CHOOSE(ROW()-1,{3,4},{1,2,3},{10}))100

Results calculated in Excel.

Mistakes people make

MistakeWhat to do instead
TextIgnored
Square of sumSUMSQ ≠ SUM()^2

SUMPRODUCT · SQRT

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📎 Practice files for this article

  • 📗
    Practice workbook: Math & rounding24 tasks on realistic sales data — type your formula, the Check column turns green when it is right. Answers sheet included.
    ⬇ XLSX · 35 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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