SIGN Function in Microsoft Excel: Examples, Pitfalls & Compatibility
SIGN in Microsoft Excel: reduce a numeric value to -1, 0 or 1 according to its direction. Includes worked examples and application-specific cautions.
Verification status: Official documentation referenced; example outcomes independently reasoned or arithmetically checked where stated. Not executed in Microsoft Excel. How formula examples are checked
Quick answer: Use SIGN in Microsoft Excel to reduce a numeric value to -1, 0 or 1 according to its direction. The official SIGN reference is the source for the function definition and platform-specific rules described below.
Syntax and arguments
=SIGN(number)
number (required): The numeric value whose sign is being classified.
Examples use English function names, comma argument separators and decimal points. Adapt formula separators to your workbook settings, not punctuation inside quoted text.
When to use it
Use SIGN when only direction matters, such as whether a signed difference is positive, negative or exactly zero. Keep the original magnitude too: a sign of 1 does not tell you whether the difference is tiny or large.
Three worked examples
Each example is independent. Where input cells are listed, enter those values first; otherwise the formula is self-contained. Expected outputs are independently checked calculations or documented error expectations, not captured results from Microsoft Excel.
Example 1: Classify a negative difference
=SIGN(-12.5)
Expected result: -1.
Only the direction is retained; the magnitude 12.5 is not returned.
Example 2: Classify exact equality
=SIGN(8-8)
Expected result: 0.
The arithmetic expression equals zero exactly in this example.
Example 3: Apply an explicit rounding rule
=SIGN(ROUND(0.004,2))
Expected result: 0.
The formula intentionally rounds to two decimal places before classifying the value. Without that rule, the positive input would have a positive sign.
Put it to work safely
Calculate the difference in one column and its sign in another. When the process has a documented tolerance, test the magnitude against that tolerance separately instead of redefining every small value as mathematically zero. Agree the precision rule before applying ROUND inside SIGN. The rounded and unrounded versions answer different questions.
Common mistakes and fixes
A small displayed zero returns 1 or -1. The stored number may be a small nonzero value. Inspect more decimal places or apply an explicit tolerance rule.
The size of a difference disappears. SIGN deliberately discards magnitude. Keep a separate numeric difference or ABS result.
Missing data receives a direction label. Validate required numeric inputs first rather than relying on how an empty or textual value might be coerced.
Microsoft Excel-specific notes
Microsoft defines the three numeric outputs directly. The comparison should be made against the value actually being classified, not against its rounded appearance in the worksheet. See the vendor reference for the current definition.
Excel and Google Sheets comparison
The three-way definition matches for the numeric cases below. Floating-point residuals and input coercion can affect whether a value is exactly zero and are not certified by these examples.
Compare the SIGN guide for Google Sheets and its official documentation. Having a guide in both libraries establishes two documented references, not a certificate of identical behavior across releases, locales or file conversions.
Related guides
Evidence and testing scope
Editorial verification: Official references retrieved on 2026-10-12. The three worked cases are included in this release’s reproducible Python checking suite. It checks the stated arithmetic, calendar or text model and the expected documented error classification; it is not the Microsoft Excel calculation engine. No native application run, UI screenshot, maximum-size benchmark or cross-version certification is claimed. Review the editorial testing standards before relying on a formula in a critical workbook.