SIGN Function in Apple Numbers: Identify negative, zero, and positive values

=SIGN(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).

SIGN is a three-way numeric indicator. It answers which side of zero is this number on? instead of returning the number’s size. Apple’s SIGN documentation specifies 1 for positives, −1 for negatives, and 0 for zero; it accepts a single numeric argument. Use it to tag profit changes, measurement deviations and inventory variances.

Create a Numbers table called Targets. Give it one header row, then enter:

In C2 of this table enter:

=SIGN(B2)

Expected result: -1 for North, because −12 is below zero. Copy C2 through C5. Expected results, in order, are −1, 0, 1, −1. Note that SIGN(-12) is −1, not 12: the magnitude disappears by design.

For an expression that compares two values, enter =SIGN(D2-E2) when D2 is actual and E2 is target. If actual is 98 and target is 100, the expected result is −1. Make your subtraction direction explicit: swapping D2 and E2 reverses the meaning.

Using the Targets table above, enter in D2:

=IF(SIGN(B2)=1,"Ahead",IF(SIGN(B2)=-1,"Behind","On plan"))

Expected result: Behind for row 2. The nested IF checks whether SIGN returns positive, then negative, then the remaining case (zero). Copied to rows 3, 4 and 5, the labels are On plan, Ahead and Behind. This uses the Apple IF function, a separate verified official function; see the IF guide for more details.

This strategy is useful when a dashboard needs a human-readable trend while keeping the original numeric difference unchanged for arithmetic. For threshold-driven flags (for example, deviations greater than 5 units) use ordinary numeric comparisons rather than relying on SIGN alone; SIGN does not tell you whether the deviation is large.

• Not the same as ABS: ABS(-12) is 12, while SIGN(-12) is −1. ABS measures size; SIGN captures direction.
• Zero exactly: SIGN(0) is 0, including when a subtraction evaluates to exactly zero. A near-zero value displayed with 2 decimal places can look like 0.00 while actually being positive or negative. Inspect underlying decimals before treating SIGN output as a data error.
• Text input: The signature expects a numeric value. If a pasted number is stored as text, check its formatting and conversion rather than assuming it will be coerced.
• Confusing negative changes with bad performance: A negative change is not always undesirable—lower spending or shorter wait times may be improvements. Phrase the status text based on your business meaning.
• Cell reference drift: When copying down a column, make sure the referenced difference cell changes to the intended row. Numbers supports relative and absolute references, documented in cell-reference help.
• Formula warning: Apple’s error guide explains how to open an error indicator; do not replace erroneous measurements with zero without investigating.

SIGN also exists in Excel and Google Sheets with the familiar three-way numeric purpose. Formulas referencing other Numbers tables may require Table Name::Cell syntax rather than an Excel worksheet name, and locale settings affect list separators in the nested IF example. Negative numbers are mathematically the same across platforms; platform-specific error presentations were not compared by execution.

• Apple ABS — size without sign.
• Apple IF — express results as descriptive categories.
• COUNTIF guide on Spreadsheet-Tutorials.com — tally rows that meet a condition.

• Apple Numbers — function documentation
• Apple’s functions syntax guide
• official welcome
• Apple cell references
• Apple IF function
• error guide
• Apple ABS

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.