>Ok, I tried this, and I'm getting incorrect results.
>
>I have a cursor with 2 columns, ID and Caption. Their widths are 4 & 50.
>
>

>sColWidths = "0,"
>sFontName = .lstAssigned.FontName
>iFontSize = .lstAssigned.FontSize
>
>FOR iColumn = 1 TO FCOUNT()
>  iSize = TXTWIDTH(ALLTRIM(FIELD(iColumn)), sFontName, iFontSize)
>  sColWidths = sColWidths + TRANSFORM(CEILING(iSize)) + ","
>ENDFOR
>

>
>This results in sColWidths being "0,2,10,"
>

Did you check Help on TXTWIDTH function?

You may try to use

iSize = TXTWIDTH(replicate('O',fsize(FIELD(iColumn))), sFontName, iFontSize)