Notching newel post

[chamfer]

Hello Folks

I want to notch a newel post over an 8x2 floor joist. Whats the norm to take out of the newel?. The newel will be bolted to the 8x2

 

[big-all]

unless its a brand new joist the exact position will be goverened by the exact location required to fit the stairs??

or am i misunderstanding the point

 

[chamfer]

Your misunderstanding the point there are no stairs

The newel is the end of a straight run of spindles and handrail if that makes sense

 

[Burnerman]

One third would usually be about right - but no more than a half of the thickness of the post.
John