This is a big decorating question and there are a lot of opinions out there. I have pretty strong opinions about this, even though I usually say "there are no rules." You still ultimately should do what you like. But I get this question a lot, so I thought I'd tell you what I prefer.
I must really miss my school days... this is not the only post I have done recently with roman numerals...
I. LIVING AND FAMILY ROOMS
A: The rug covers the entire seating area
This is my favorite option. Of course it is, since it is the most expensive and hard to accomplish (haha).
In this method, the rug should usually be larger than you might think and all feet of all furniture in the seating area should be on it. So a console table on the wall isn’t included in that, but the sofa and chairs, for example, would be.
This is really good, but I think the rug could be just a foot bigger behind the sofa sides:
And some I think are just about perfect:
Sometimes, when the sofa is up against the wall, you have to leave the back legs off the rug (you don't want the rug hitting the wall). I'd prefer this layout with this rug if the sofa were pulled out from the wall, with a console table behind it. Only the sofa would be on the rug, not the console:
I realize I sound like a nut here, but I wish this were one foot bigger. Still beautiful though:
This is so pretty! I would just love to see that rug one size larger and underneath the feet. Not everyone agrees with me though. It might just be me, but it seems like weird symmetry to have it in front of and to the left of the sectional here and it would bug me in my own home:
This is what really bugs me. This is a gorgeous room, but I wish those chairs could be pulled out of the corners and onto the rug:
One note: Did you notice how most of the examples in this section are sisals or other neutrals? That's important I think. Colorful rugs can be overwhelming in huge sizes, so with those, I prefer to layer (Option C). But if it is going to be neutral, get it big.
B: The rug is an accent and isn't under any of the seating
This is my least favorite, although I know some people don't like to cover a lot of floor, so they prefer it. So do what you like.
These show the area rug under none of the seating:
The next two are good examples of what I don't do. Still beautiful rooms, so I'm not criticizing them at all, and whoever did them obviously prefers this, probably because of the cool floors (Can you tell how much I don't want to criticize other people's work? I hope so). I just personally would go crazy with this, and think a much larger rug would tie it all together better and make the seating area better defined:
This is a furniture company, so I'm not as hesitant to criticize. I really don't like this:
One note: I think this next one is also a good example of what works. The large rug is under all the sofas, but not at all under the chairs. So, it works (although I'd still prefer it under all). I'd hate if the chairs were half on it, but wholly off works. Especially because it is a big rug and fits the scale of the room. Does that make sense?
I actually just did this for a client and I think it works, here, too:
C. LAYERING RUGS
This is my second favorite option for neutral living rooms, but my favorite for colorful ones. Do you think I'm crazy yet? I hope not. It's just that a neutral color scheme can handle a huge rug - helps it actually - by defining the seating area and tying it all together. Here is my old family room. I hate that the white sofa is off the rug. But the huge rug worked because it wasn't too busy and it tied the colors together. If it had been two feet wider I may have never changed the room:
But in a very colorful, energetic room, all that color or pattern can get overwhelming. This one overwhelms me, for example:
So what I prefer in this situation is a sisal or the like as the base (large enough for all seating to be on it), and a colorful one layered on top in a smaller size, like Emily Henderson did here:
I also like these:
This one is a perfect example of what I mean. A purple rug large enough for the space might be overwhelming (or not available), so this works instead:
I love this room, and think it would be perfect with a sisal under the rug shown:
I think the rules are different in bedrooms, whether they are carpeted or not. My only thoughts here are to make sure the rug is big enough, and always lay it horizontally facing the bed (I have never seen it the other way that I like).
Here is what I think works:
I don't like when the rug doesn't go close enough to the top of the bead. Here, I would like to see it just in front of the end table. But, if the room had wall to wall carpet under the accent rug, it's not as important to place it so close to the head of the bed. The "rule" is that your feet should hit rug/carpet when you stand up from bed:
Lovely room, but I would move the rug up or layer one under it:
And this is an example of a rug being placed vertically to the bed, rather than horizontally. It looks weird to me because I just think the rug should be wider than it is long. I can't explain why, except for general aesthetics - it looks better to me the other way, always:
Dining rooms are a bit different, too, and I only have two thoughts about them.
1. I don't use round rugs. Ever, ever, ever under any circumstances. I can't stand them and have literally never seen one I think looks good. That could be just me, though.
2. The rug should be big enough that when people are sitting at the table, the back legs are still on the rug - usually about 2' past the table. And the storage furniture like buffets and credenzas need not be on the rug:
This one is a bit small I think:
This would drive me crazy:
I did this room several years ago for a client:
This is the rug we used. They are custom cut for $6.75 a foot:
A lot of people I talk to don't know that PB does custom sizes, too, and they are 20% off now: