LEN (Transact-SQL)

string_expression

Is the string expression to be evaluated. string_expression can be a constant, variable, or column of either character or binary data.

bigint if expression is of the varchar(max), nvarchar(max) or varbinary(max) data types; otherwise, int.

If you are using SC collations, the returned integer value counts UTF-16 surrogate pairs as a single character. For more information, see Collation and Unicode Support.

The following example selects the number of characters and the data in FirstName for people located in Australia.

USE AdventureWorks2012;
GO
SELECT LEN(FirstName) AS Length, FirstName, LastName 
FROM Sales.vIndividualCustomer
WHERE CountryRegionName = 'Australia';
GO

Reference