Flexgrid Column Width

In my flexgrid i have 20 columns.

To assign width for each column i wrote code as

FlexGrid.Width / 20

I am trying to divide the width of the flexgrid by number of columns.

Now the width of column becomes so small that it occupy only 5% of the flexgrid, where as i want that all the columns should occupy the whole flexgrid.

Are the columnwidth and flexgrid width are in the different units?
Kindly help.

Thanks :wave: