Usually depends on what I'm wearing:
If I'm wearing jeans, it doesn't really matter since it's clipped to my pocket. Typically, I like it heavy so around 5-6 oz
If I'm wearing shorts or sweats (running/exercise), I rather it be light, so around 2-4 oz (g10 scaled knives usually work)
If it's dress pants, I really want it to be light, since I can't clip it and it's free floating in my pocket. So around 2-3 oz.