Math & Trig
SQRT Function in Excel
Returns the square root of a number.
Syntax
- =SQRT(number)
Arguments
- number (required): The number to find square root of
Examples
- =SQRT(16) - Square root of 16 - Result: 4
- =SQRT(2) - Square root of 2 - Result: 1.414...
Excel SQRT function documentation
- SQRT returns the square root of a number.
- Syntax: =SQRT(number). number must be non-negative.
- Use in geometry, statistics (RMSE), and financial volatility calculations.
- Related: [POWER](/functions/power/), [ABS](/functions/abs/), [SQRTPI](/functions/sqrtpi/).
SQRT syntax and errors
- number >= 0 required — negative returns #NUM!.
- SQRT is same as number^0.5 or POWER(number, 0.5).
- Text numbers may coerce; text letters → #VALUE!.
- For complex numbers use [IMSQRT](/functions/imsqrt/) in Engineering.
Step-by-step: RMSE from error column
- Step 1 — Squared errors in column D.
- Step 2 — Mean squared: =AVERAGE(D2:D100).
- Step 3 — RMSE: =SQRT(AVERAGE(D2:D100)).
- Step 4 — Label column "RMSE" for forecast accuracy report.
- Step 5 — Compare models by lower RMSE at same horizon.
SQRT vs POWER vs ^ operator
- SQRT(x) — clearest for square root.
- POWER(x,0.5) — general exponent form.
- x^0.5 — same as POWER in Excel.
- Math hub: [/categories/math-trig/](/categories/math-trig/).
Worked examples to copy
- Basic: =SQRT(16).
- Hypotenuse leg known: =SQRT(c^2-a^2) with POWER for squares.
- From cell: =SQRT(A2).
- Guard negative: =IF(A2>=0, SQRT(A2), "NA").
People also ask
- SQRT negative? — #NUM! in real SQRT.
- SQRT of blank? — 0.
- SQRT vs RSQ? — RSQ is R-squared correlation; different function.
- SQRT Google Sheets? — =SQRT(n).
Common errors
- #NUM! if number is negative
Use cases
- Distance calculations
- Standard deviation
- Geometric formulas
Frequently asked questions
- How do I calculate the square root of a negative number in Excel? SQRT returns #NUM! for negative numbers since square roots of negatives are imaginary. Use IMSQRT for complex results: =IMSQRT(-16) returns '4i'. Alternatively, use =SQRT(ABS(number)) if you just need the magnitude.
- How do I calculate cube root or nth root in Excel? Excel doesn't have a CBRT function, but use POWER with fractional exponent: =POWER(27, 1/3) for cube root (returns 3). For any nth root: =POWER(number, 1/n). Example: 4th root of 16 is =POWER(16, 1/4) = 2.
- How is SQRT used in distance calculations? The Pythagorean theorem uses SQRT: distance = SQRT(x² + y²). In Excel: =SQRT(POWER(x2-x1,2)+POWER(y2-y1,2)) calculates distance between two points. For 3D: add POWER(z2-z1,2) inside the SQRT.
Editorial review
- Reviewed by Excel.Directory Editorial Team. Updated May 2026.
When to use SQRT
- Distance calculations — common Math & Trig scenario for SQRT.
- Standard deviation — common Math & Trig scenario for SQRT.
- Geometric formulas — common Math & Trig scenario for SQRT.
SQRT in the Math & Trig category
- Browse all Math & Trig functions at /categories/math-trig/ for related formulas.
- SQRT syntax: =SQRT(number)
- number (required): The number to find square root of
- Confirm SQRT arguments match the syntax shown above before filling down.
- Lock table and range references with $ when copying formulas across rows or sheets.
Formula checklist before you copy down
- Confirm SQRT arguments match the syntax shown above before filling down.
- Lock table and range references with $ when copying formulas across rows or sheets.
- If results look wrong, check for text stored as numbers and invisible spaces with TRIM.
- Spot-check three known input rows manually against expected output.
Related Excel functions
- POWER (/functions/power/): Returns the result of a number raised to a power.
- SQRTPI (/functions/sqrtpi/): Returns the square root of (number * pi).
Errors to watch for
- #NUM! if number is negative — review causes on linked error pages in the directory.
Copy-paste audit workflow
- Enter SQRT on three test rows with known expected output documented on a QA tab.
- Fill down only after absolute references are locked on lookup tables and rate tables.
- Compare against manual calculation or a calculator for financial and statistical functions.
- Search this directory for comparison guides when choosing between similar functions in the same category.
SQRT worked examples to copy
- =SQRT(16) — Square root of 16. Expected result: 4.
- =SQRT(2) — Square root of 2. Expected result: 1.414....
SQRT reference summary for crawlers and offline review
- SQRT belongs to the Math & Trig category in Excel. Returns the square root of a number.
- Full syntax: =SQRT(number). Open /functions/sqrt/ for parameters, FAQs, and related pages.
- Common mistakes: #NUM! if number is negative
- Pair this function with comparison guides when another Excel formula might fit the same task better.
- Review fix-excel-formula-errors when unexpected errors appear after upgrading Excel or sharing across locales.