LEN returns the length of a text string. For example, =LEN("BK-1042") has an expected result of 7, and =LEN("A B") has an expected result of 3 because the internal space is included. Use LEN to check text-entry lengths or flag identifiers that do not match a known format; it does not tell whether an entry is semantically valid.

=LEN(text)

text is required: the KDE release XML declares one parameter of type String and a whole-number return type. There is no optional length or count argument, and the 26.08.2 code registers LEN with its single-argument function implementation (func_len). Its C++ body converts the argument to a QString and returns the string’s length().

The English handbook uses LEN(text) with no argument separator because it has one argument. =LEN(A2) references a cell; =LEN("A B") is a quoted literal. Different locales can affect text entry, number conversion and displayed formula conventions, none of which were natively tested. Do not assume Excel’s Unicode compatibility mode applies to Calligra’s Qt implementation.

Create a new sheet with Entered text in A1 and Number of characters in B1. For row 6, leave A6 completely empty; the other A-cells contain the exact strings shown, including spaces. Enter =LEN(A2) in B2 and fill down through B7.

The A4 spaces are important: visually blank characters can be easy to miss. The table was checked with independent Python string-length assertions for ASCII-only input (with A6 represented by an empty string). The application itself was not run, so the empty-cell result is an expected value under the pinned source’s text conversion, not an observed output.

Suppose every product identifier must be exactly seven characters long, including the hyphen. For row 2 enter:

=IF(LEN(A2)=7;"Length OK";"Check code")

With A2 = BK-1042 the expected result is Length OK. With A7 = AB-12, the corresponding formula referencing A7 has the expected result Check code because the input is five characters long. This verifies only length, not allowed letters, number range, uniqueness or SKU ownership. Keep the original identifiers visible for auditability; do not automatically discard records that fail.

To check how many characters remain after explicitly removing extra spaces, compare =LEN(A4) with =LEN(TRIM(A4)) using A4 = AB ; the first is expected 6, while the second is expected 2 if the documented TRIM behaviour removes leading and trailing ordinary spaces. The TRIM comparison is documentation-based and independently inferred, not a native joint-function test. Avoid extending this guarantee to nonbreaking spaces or invisible Unicode characters without inspection.

• Too high a count: check for leading and trailing spaces, which are easy to overlook. The independent ASCII test LEN(" AB ") equals 6.
• Different length than the visible code: ensure the cell contains the expected underlying text. Numbers, dates and displayed number formats can differ from the source string passed through Calligra’s conversion layer; precise coercion is not natively tested.
• Zero or blank result: check that the input cell is populated and that the formula references the intended row. A zero for truly empty text is consistent with the source’s string-length calculation.
• Unicode and surrogate pairs: func_len calls QString::length(). This does not establish the same grapheme or emoji counting as a user’s perceived characters, nor parity with Excel compatibility versions. The examples intentionally use plain ASCII and require further native Unicode validation before broader claims.
• LENB alias inconsistency: the official handbook describes byte-based LENB, but the pinned C++ registration sets LENB as an alternate name for the same func_len. Do not claim a separate byte-counting function from the label alone or publish a duplicate guide until its installed behaviour is established.
• Unexpected formula error: type =LEN(A2) or =LEN("word"); confirm the leading =, quotation marks for literals and valid cell reference. KDE’s function page defines one text argument, not a range-aggregation rule.

Microsoft Excel also documents LEN(text) and explicitly counts ordinary spaces. ASCII identifiers like BK-1042 are suitable cross-software sanity checks. Excel’s current documentation mentions compatibility-version differences for Unicode surrogate pairs, and explicitly treats variation selectors separately; none of those Excel rules has been tested for Calligra. Workbook import/export, arbitrary Unicode strings and non-ASCII locale conversions remain open validation tasks. No test of LibreOffice or Google Sheets runtime occurred.

• Calligra Sheets — function documentation
• sheets/functions/text.xml
• sheets/functions/text.cpp

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

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