Answer:
Both scales measure the intensity of rotating storms (the F or Fujita scale rates tornadoes while the Saffir-Simpson scale is used for hurricanes).
Both scales have corresponding wind ranges for each category, and the strongest category on each scale is a rating of 5.
However, there are some differences. The Saffir-Simpson scale uses direct wind speed estimates while the Fujita scale rates tornadoes based on damage. Also, while the Saffir-simpson scales has 5 levels, category 1 though category 5, the Fujita scale has 6, F0 through F5. F0 wind estimates correspond roughly to those of a tropical storm. Also, the wind ranges of most categories differ significantly, especially in higher categories.