Hi

If the default grid system follows a 12-column layout. 

then the dimension of 1 "col" would be calculated as 

1 col = Total Available Width / 12

For example, if the container has a width of 1200 pixels, then each column (1 col) would have a width of:  

1 col = 1200 / 12 = 100 pixels

So, in this case, 1 col would represent 100 pixels.

Hope this helps 

Thanks