Call a contractor and get a kitchen /bath designer on site. With the contractor. I'd assume you have already learned the DIY thing isn't going to help you in short or long term : )

A nice master bathroom is a good investment.

Get 2 GC to get estimates. They'll help you determine which walls can be expanded or not.

Then post a floor plan with notes of what is feasible, so Houzzers can help.

Ask GC where recessed storage is possible. Avoid plumbing, electrical, HVAC obstructions in walls.

Here's some samples of recess into wall options

Look forward to seeing the sketch.

Please note areas that cannot be moved on sketch & or areas that can.

Houzz is a great place to get design ideas to give your GC;)

So I made a sketch of my bathroom. Where the doors are I struggled with getting them to look right, but you can see from the photo just how much space there is between the two doors. The door near the towel bar is a storage closet that is about 2’3” wide and 1’ 10” long and has wire shelving all the way up. Behind the cabinet is my master closet. The 6’10” you see beside the closet door is from the edge of the frame to the back wall. The electrical is only on the 3’ wall beside the entry door and then above the vanity is another electrical wiring for the vanity light. And it’s hard to read the measurements for the L shaped wall near the tub and toilet but it’s 9” near the shower head wall and then the wall near the toilet is 11”. Measuring from the back wall near the toilet to the opposite wall was 6'.

The small spaces need a Kitchen & Bath design specialist more than the larger spaces. You will have a better plan to go to your GC to price and end up with a better solution.

Is this the only tub in the house?

What about this over toilet.

Can also put doors with frame over with mirrors if you like.

Bathroom general dimension guidelines.

Currently a 1 sink vanity will fit.

Ways to maximize the storage in a bathroom closet.

pullouts for deep closets for easier access, a light in closet a bonus.

A pantry cabinet installed into a closet. with adjustable shelving.

Example how a recess storage can have doors with framing.

I agree.

Unfortunately, the current master bath space seems like it was an afterthought.

Do you think you will keep the walls as is or move walls to make master bathroom bigger?

It could be worse. ..

Do you want to keep a tub in there or are you considering a walkin tiled shower with seating & glass doors?

Unless a closet can be built elswhere in the bedroom.

Sounds like the walls should stay, because not enough to make a difference.

A nice walk in tile shower with glass doors is a great idea. It will make the master bathroom look bigger.

With the right designer, I think you can get a real gorgeous remodel done. Looks like there should be enough space to do it all!