Does anyone have a way of adjusting the field width?

I presume Field Width is in Pixels and Characters are different.  Is there a translation chart for how much Field Width is necessary for a number of characters?

I use a modified Purchase Order Report form and the field width makes no sense.  It appears you cannot adjust the width of the fields. 

Part # - Width 105                  Characters – Auto (15)

Description – Width 203        Characters – Auto (75)

Alpha Part # - Width 133        Characters – Auto (50)

Unit – Width 25                      Characters – Auto (10)

Quantity – Width 83               Characters – Auto (12)

Price – Width 80                     Characters – Auto (15)

Total – Width 94                     Characters – Auto (12)