It depends. Some 4x5 photographers use little movements, perhaps some front tilt, which others use movements boldly, perhaps using large amounts of front rise. The mm of front rise that you might want to use will probably also depend on the focal length of the lens.

After accounting for the filmholder rails, the actual usable dimensons of a 4x5 film are about 95 x 120 mm, for a diagonal of about 153 mm.

I use a 180 mm lens as my "normal". I consider myself I fairly bold user of movements -- for another question, I searched my notes, and found that I have never used more than 53 mm of front rise with my 180 mm lens. This implies I've only used a circle of coverage of 245 mm diameter. Maybe a little more if I used some front tilt at the same time.

The definition that "normal" = "diagonal" would have 150 mm be the normal focal length for 4x5. 210 mm has also been popular as a standard/normal lens for 4x5, probably because it offers essentially unlimited movements. If you don't want to go quite so long, 180 mm also does the same.