>It did not work properly. I got the answer as 66 with following command
>

>?FONTMETRIC(7,"MS Sans Serif",9)*LEN("WWWWWW")
>

>After changing the width to 66 also, last 'W' did not get displayed fully.

Don't forget that the standard margin for a textbox is 2 (so I guess that would add 4 to your calculated width).