The 1996 Ford F-250 takes 18" wiper blades on both sides front. See sources and related links below. Do not buy wipers just by length however, and be sure to lookup exact wiper blade part numbers for the brand wiper you decide to purchase by vehicle make, model and year. This ensures correct length AND attachment.
It's a 20 in. wiper blade
The 1998 Ford Ranger takes 18" replacement windshield wiper blades on both sides front.
For a 1999 Ford Taurus the driver side wiper blade is a size 24. The wiper blade on the passenger side is a size 20.
The 2005 Ford Explorer takes 20" replacement wiper blades on both sides front and a 16" rear.
19" Front9" Rear
The 1997 Ford F-Series Pickup takes 22" replacement wiper blades on both sides front.
The 1991-2002 Ford Escort takes 20" drivers side and 18" passenger side replacement windshield wiper blades on the front and if applicable, a 14" rear wiper blade.
The 1996 Ford Windstar takes 24" drivers side, 20" passenger side and 16" rear replacement windshield wiper blades.
The 1994-1997 Ford Aspire take 20" driver side and 16" passenger side replacement windshield wiper blades.
The 2005-2007 Ford Five Hundred takes 24" driver side and 20" passenger side replacement windshield wiper blades.
The 1980-1996 Ford F-Series Pickup takes 18" replacement wiper blades on both sides front.
The 2009-2010 Ford F-Series Pickup takes 22" replacement wiper blades on both sides front.