SQRT function
SQRT returns the square root of a number: the value that, multiplied by itself, gives the number. It shows up in geometry (side lengths, distances) and statistics, where a standard deviation is the square root of a variance.
- Available in
- Every current version
- Category
- Math functions
- Returns
- The positive square root.
- Google Sheets
- Works the same in Google Sheets.
Syntax
=SQRT(number)
| Argument | Required? | What it is |
|---|---|---|
number | Required | The number to take the square root of. It can't be negative. |
Examples
Each result below is calculated from the sample sheet by our formula engine, the same one that grades the practice.
| Cell | Formula | Result | What it shows |
|---|---|---|---|
| D2 | =SQRT(B2) | 14 | Side of a 196 sq ft square room: 14 ft |
| D3 | =SQRT(B3) | 48 | Standard deviation from a variance: 48 |
| D4 | =SQRT(B4) | #NUM! | #NUM!: negative numbers have no real square root |
Try it live
This is the sample sheet. Change any number or text, or edit a formula, and the results update.
Show the sample data as a table
| Measure | Value | Square root | |
| Square room (sq ft) | 196 | 14 | |
| Variance of daily sales | 2304 | 48 | |
| Negative input | -16 | #NUM! |
Practice SQRT
Graded instantly, then re-checked on changed data.
Straight-line distance
D2, use SQRT to find the straight-line distance (the square root of each distance squared, added together). Fill down to D6.Common mistakes
| What you see | Why, and how to fix it |
|---|---|
| #NUM! | The number is negative. If only the size matters, use =SQRT(ABS(A2)). |
| Needed a cube root | SQRT only does square roots. Use a fractional power instead: =A2^(1/3). |
| #VALUE! | The cell holds text. Check for numbers stored as text. |
Tips
- Straight-line distance between two points: =SQRT((x2-x1)^2+(y2-y1)^2).
Questions
How do I calculate a square root in Excel?
Use =SQRT(A2), or =A2^0.5, which does the same.
How do I calculate a cube root in Excel?
Use =A2^(1/3) or =POWER(A2,1/3).
Why does SQRT return #NUM!?
The number is negative. Square roots of negative numbers aren't real numbers.
Last reviewed October 2026. Every example result on this page is calculated live by the Spreadsheet Practice formula engine.