One mirror for 2 sinks? Where do the sconces go? They should be at face height for the best lighting and usability; that means 2 of them will be in the middle of the mirror.

A bathroom, like a kitchen, is primarily a workspace. You need it to function for things like shaving, applying makeup, brushing your teeth, inspecting your skin and teeth and gums. Proper task lighting is critical, and a mirror over each sink is necessary. I'd use 2 rectangular mirrors and 3 sconces.

You seem to be putting form before function.

Each space is 50 inches so its 2 sinks, 2 mirrors and 4 sconces.

Yes to taping it out and maybe even tape over the mirror in whatever space you are currently using so you can see what you'll be missing. Rectangular mirrors make more sense to me. We have a 7 foot vanity with 2 sinks, 3 banks of drawers, and we put 2 rectangular mirrors and 3 sconces, and love the result.

thanks so much for the comments. I can't do 3 sconces because i have a middle cabinet. My thought on round mirrors is that give me more space but good to know about the round mirror cutting things off. we did go draw it out today and that was a huge help. THANKS!

I'd give each sconce about an inch and a half of breathing room on either side...so factor in 9.5" wide per sconce x2 for each side. If I'm doing the math correctly, subtract 19" (9.5" x 2 sconces) from 50" and that leaves you with 31" of mirror to work with. You *could* try squeezing in a 32" round mirror, but that might be too crowded looking. Best of luck!