How much should a 35 year olod man weigh?

This depends on height.

Height in centimeters minus 100 equals ideal body weight in Kilograms for a man

Height in cm minus 105 equals IBW for women.

This is a standard equation used in the medical world. It tends to be on the low side. and also depends on body habitus.

inches X 2.54 = centimeters

Kilograms X 2.2 = pounds