[CountChars]Any Text[/CountChars]
To count the number of letters in something, put the text inside a [CountChars] context.
Example (normally you would put the following text into a .tpl file on your server and use a web browser to link to it):
Try It!
In the example above, the displayed text will be
9
The number displayed is the number of characters inside the context -- the count includes carriage returns, tabs, linefeeds and other characters that are sometimes invisible.