SQRT Function in Apple Numbers: Find a square root

=SQRT(num)

Apple’s version 15.4 Functions Help reference gives this function name, argument order and argument types; checked on 2026-10-11.

All parameters shown as required above must be supplied; only arguments explicitly labelled optional may be omitted. Enter = before the function. Apple writes argument lists with commas in its English help; when the user’s decimal separator is a comma, Apple says to type semicolons between function arguments. This does not change any cell values, and a one-argument function has no separator to change. See Apple’s functions syntax guide.

Version and device scope: The specific documentation URL is the Apple 15.4 Functions Help page. Apple describes the in-app Functions Browser for Numbers on Mac, iPhone and iPad, and for iWork apps on iCloud.com (official welcome). That help entry does not establish the first Numbers release that supported this function, nor that every historical macOS/iOS/iPadOS/web edition handles every edge case identically. No first-supported version has been invented; native version-by-version testing is still pending.

Numbers references: Examples below enter formulas in the same table as the data, so B2, C2, and B2:D2 are legitimate Numbers cell references. For references into a different table, Apple documents forms such as Table Name::B2 or Sheet Name::Table Name::B2; use the formula editor to select cross-table cells (Apple cell references).

Use SQRT to convert an area into the side length of a square, calculate a distance from horizontal and vertical displacement, or reverse a squared calculation. Apple’s SQRT help defines one numeric argument; its examples include both perfect and fractional squares. In ordinary real-number arithmetic, SQRT chooses the nonnegative square root—SQRT(144) gives 12, rather than ±12.

Create a Numbers table called Squares with these header and data rows:

In C2, within the same table, enter:

=SQRT(B2)

Expected result: 12 cm. A square whose area is 144 cm² has sides 12 cm long, because 12 × 12 = 144. Copy the formula to C3 and C4; the expected results are 3.5 and 9 cm. The reference changes by row when copied normally.

An even quicker independent example requires no table data:

=SQRT(12.25)

Expected result: 3.5, matching Apple’s own example. Formula cells are numeric: apply cell formatting (for example, two decimals) if your reporting needs consistent appearance.

Create a second table named Paths:

In D2 of Paths type:

=SQRT(POWER(B2,2)+POWER(C2,2))

Expected result: 15 metres. Pythagoras gives SQRT(9² + 12²) = SQRT(81 + 144) = SQRT(225) = 15. Copy to D3 for 5 metres. Use this only when the two dimensions are perpendicular and share the same length units. If B and C mix feet and metres, the formula still computes but the interpretation is wrong.

Apple explicitly confirms that POWER(x,y) and x^y agree, so =SQRT(B2^2+C2^2) is the equivalent alternative. Enter formulas in the result column rather than any cell that belongs to the referenced range.

• Negative input: The square root of a negative real number is not a real number. If your source is negative, determine whether the data are invalid or whether a different mathematical model is needed. We did not execute Numbers to certify the exact displayed error string.
• Blank or text input: Verify the value is a number, not a pasted label such as 144 cm². Store the number in the cell and put units in its column header. Numeric-looking text from imports may need conversion.
• Confusing square and square root: SQRT(9) is 3, while POWER(9,2) is 81; they reverse different operations only when the input is nonnegative.
• Rounding: SQRT(2) is irrational. Displayed rounding is not proof the stored answer is an exact rational fraction; use an explicit rounding function only if the calculation requires a rounded result.
• Formula shows an error triangle: Verify references and data types, then use Apple’s documented error-inspection process. Watch for accidental circular references.
• Dates and durations: The official signature expects a numeric value. Convert a duration using documented duration functions when that is the real intent; do not assume SQRT interprets a formatted date as a physical measurement.

Microsoft Excel, Google Sheets and Apple Numbers all use the recognizable SQRT name, but copy/paste of formulas referencing other tables may require rewriting the qualifiers. In Numbers, a different table can be referenced with the table name and two colons, such as Squares::B2, if needed. Real-number square roots differ conceptually from solving an equation that has both positive and negative roots.

• Apple POWER — general exponents and squared values.
• Apple PI — circle-related formulas.
• Spreadsheet-Tutorials.com SUMIFS guide — a different operation: adding values subject to criteria.

• Apple Numbers — function documentation
• Apple’s functions syntax guide
• official welcome
• Apple cell references
• POWER(x,y) and x^y
• Apple’s documented error-inspection process
• Apple PI

Verification status: Official documentation checked; example outcomes were independently reasoned or arithmetically checked where applicable. Not executed in Apple Numbers.

• No genuine Apple Numbers screenshots are included; this guide does not use mock application images.