It is a simple 90 turn, cut each angle at 45 degrees, and attach one to the other as you prefer. Use care if bolting the rail/newel joint as you will be bolting into the small short-grain return, and it would be easy to split it.
They also sell factory-made rounded 090's for situations like this, but they can be tricky to cut down to length without experience and a good saw. They would entail doing two stair-bolt attachments.
If, OTOH, you are asking how to level off the rail and do a 90 return with one compound cut, well, that cannot be done. The leveling off and the 90 have to be done separately, and a 3rd piece of rail is needed; it ends up being an odd little angled wafer of stock, with a 40* miter in one direction, and a 45* miter in the other. The top of the main rail gets a corresponding 40* cut, and the short return gets the other 45.
It's not worth it, unless the square part of the newel is so small that the rail return lacks the attachment space and you have an ugly overhang. I think that regular 2 1/2" newels are okay with the one-turn type of cut, with regular size rail.
Casey

Thanks for the quick response. Let me see if I understand you. I would need to have three pieces of handrail to make this happen. The first would connect to the newel post (it is a 3" newel post). This piece (#1 on dwg) would be flat on one end to bolt directly into the newel and the other end would have a 45ð miter cut to mate up to the second piece to make the 90ð turn. The second piece (#2) would then have the corresponding 45ð miter and then the other end would have to be mitered to match the angle of the decent of the handrail going down the stairs (the alpha angle from the picture). The third piece (#3) is the handrail going down the stairs. Is that right?

Is there any way to do this better or with just two pieces. I know of the curved piece and that is a last resort but the way I have it drawn sure creates a lot of joints which will just weaken the stability.

Here is a link that might be useful: {{!gwi}}

Hi,
You understood my second option perfectly. The first option just has the short return piece meeting the newel while rotated or canted at the angle of the staircase. This is easiest as it does away with the transition, and most builder-grade new construction defaults to this simpler alternative. Just remember that your horizontal balcony or landing rail must be at 36-38", but the stair handrail must be at 32=34" above the nosing of the treads. This creates a great disparity, and it is very possible that the square part of your newel (assuming that it has a turned section in the middle) will not be capable of catching both of these rail heights. That's what goosenecks are for. The gooseneck raises the terminus of the railing to the very same height above the landing as the horizontal rail, thereby creating a visual unity to the whole assembly.
It's not that a gooseneck is mandated by code, it just looks better, and lets you use a newel with a smaller square section. (newels are made with as longer and shorter square sections.)
Just make sure you understand that the stair rail must be within the 32-34" range.
Casey

Rotating the handrail! That's brilliantly simple! For some reason, I just couldn't visualize the setup until you said that. Thanks a ton!!!

As for the railing height and such, I am using a "landing newel" for the top newel. This has an extended flat square section so two different height handrails can mate up to it. Once I lay everything out, I'll see if I need that curved piece of if I can make it work.

Thanks again. I love this site!