2.5 to 3.0 feet

On the bare wall side, my recessed are 29" from the wall. The wall starts being light about 12 inches from the ceiling. Closer will give you light higher up on the wall but a brighter wall. But what I have doesn't make any difference unless you use the exact same can, baffle and bulb. If you are flexible on your bulbs, you could drop the wattage (lumens) down if the light on the wall blasts you out of the kitchen.

Norm, if you did 3ft and used a 4" fixture with narrow beam halogen how much light would you get on the wall?
Thanks,
Bob

Bob
I assumed that these fixtures were for general or ambient light.
I wouldn't use a 4" fixture with a 50PAR20/NFL as this would provide tight beam output and , hence very focused light instead of diffused output.
I prefer 50PAR30/FL or 50par30soft par's for general lighting.
That's what's interesting in lighting design...we all have our own solution, and there's always many correct solutions