Probably a 9 X 12. In order to know for sure, use painters' tape to put an outline that size on your floor. 9 X 12 is a standard size. If you find a standard size doesn't work, any carpet retailer can custom cut and bind the edges of one of their remnants or their stock carpeting to make an area rug the perfect size. There is a wider variety of stock carpeting available than you might think if you haven't looked in a while. It's not all just different colors of plush.

As a rule, at least the front two legs of all pieces of furniture in your room should be on your rug. Someone will probably come along and photoshop in a few different rugs for you. You can always take a cushion (or if you have arm covers those are much easier to deal with) to the store for matching.

The wall art over the sofa is contemporary, but the picture over the console with the pictures is less contemporary. Which way do you want to go with the rug?

For sizing of the rug, it's good to have them either half way, fully under or even 6" or more out from your sofas/chairs. Here are some styles you may find appealing. Something with greys/beige and warmer tones of yellow or gold would be nice to see here with maybe some hints of blue or light green to pick up on your accessories.

Hope that helps!

https://www.houzz.com/products/bashian-digna-ivory-gray-area-rug-5-x7-6-prvw-vr~94224497?lid=72680146

https://www.houzz.com/products/kaleen-hand-tufted-middleton-graphite-wool-rug-3-x5-prvw-vr~54045818

https://www.houzz.com/products/weave-and-wander-pellaro-rug-pewter-gray-5-3x7-6-prvw-vr~62790580

https://www.houzz.com/products/nourison-euphoria-area-rug-gray-5-3x7-3-prvw-vr~96004055

Here is the difference between the 8x10 and the 9x12 rug sizes in your room.

Really like the top rug, would you know who sells that one or any of the other ones? Thanks for photoshopping the rugs, it gives me a better visual.

Size it right no matter which one. You don't want a skimpy look.

Upon taking a harder look at your room, I think I have a better layout for your furnishings. There's no escaping the diagonal walkway in your room but you have quite a few hurdles to jump over to get from one end to the other. The layout below could work better for your room.

Beverly

Like your layout, will have to try it. Can you tell me where to purchase the rugs.

All the rugs I posted were from Rugs-Direct.com. I searched under Aqua Area Rugs. However, none of these rugs are exclusive to that vendor. You could probably find them on lots of websites.

Provide a pic showing the printed chair more prominently. I think that will be your limiting factor when selecting a rug.

A bit deeper has a dressier look --

https://www.homeshoppingmalls.com/2020-teal-area-rug-nourison-nr204-99446363268?utm_source=gs&utm_medium=cpc&msclkid=20e015a0681f1b14b68f74501f00d30b

Nourison 2020 NR204 Area Rug, Teal, 9'2" x 12'5" · More Info

With wall item, with color of pillow -- ?

Izmir Rug, Taupe and Aqua, 5'3"x7'6" · More Info

I like it!

So much better!

Better! I love the deep color of the first rug that @everdebz posted! Something rich will pull the room together. Is 9x12 still the right size?

Some ideas for rugs. More modern first

Or a showstopper?

The room seems more spacious with the new layout

Is the room all light neutral, and dark table in the center? - Imo, a rug with hue like your own pillows is more interesting, and not "too much."

Teal, Beige, Gray, Light Gray, Dark Brown, Sky Blue.

Kaleen Rosaic ROA07 8'x11' Teal Rug · More Info

Velvet 2 Piece Lumbar Pillow Cover Set, Agate Green, 2 Piece, 14"x26" · More Info

Middle of sofa with yours at the ends... has some lines like wall item... soft colors like chair.

Global 16" x 24" DYA Beige Oriental Accent Pillow Cover Only · More Info

Hard for me to link wall item's straight lines and the swirly upholstery. If you had one or the other, it'd be easier for you, I think... just a mention. And think metal tables also have a link with wall's wood item... but not as much with chair.

Since your foyer walls are sage, I thought I'd try that color for your rug

If the rug is too blue or aqua it won't work in your room.

Excited to share that Beverly of FLADeziner won Best of Houzz Service 2022!

Actually the foyer is Farrow & Ball’s Down Pipe….a real dark gray.

Reevaluate your furniture layout before buying a rug. Make sure that’s where you want it before figuring out the rug size and spending $$$.

https://youtu.be/jlrLPmDt6LY

Checking in - entry dark grey - is LR same paint, and furniture for sure looks grey, yeh?

The living room is BM called Fieldstone, when the sun is shining it’s gray when it’s darker out it’s more of a green-gray & the sofa is gray.

A bit more toward rug decision - adding to current tripod look, and metal iron legs - if entry had a unique look like this, would a rug choice be easier, cause this leans toward hand-made, and look of your wood item above sofa...?

Contemporary Brown Wood Wall Mirror Set 47936 · More Info

Not sure what you mean.

WOW!!! What a difference that made. Loving it 😊

I like the new layout. Since you have end tables, you might want them to sit entirely on the rug so they don't tend to wobble. Use painter's tape to tape out the rug size on the floor; at minimum it should go half way under the sofas and extend past the ends by a foot or so. However, that may cause issues with the end tables being secure or exactly level (depending on the rug's thickness.) What's the plan for your window treatments?

I think a 9 x 12 would fit perfectly ! You can take some ideas from this page.