The most common decorating regret isn't a paint color. It's a rug that's too small.
It happens for a good reason. An 8 x 10 has twice the floor area of a 5 x 8, and it often costs close to twice as much. In the shop the smaller one looks plenty big. Then it goes down in the room, floats in the middle like a bath mat, and suddenly the sofa looks cheap and the room looks smaller.
You don't need a rug calculator to get this right. You need a tape measure and one sum.
Why most living room rugs end up too small
A rug has one job in a living room: to hold the seating together as one group. When the rug only reaches the coffee table, every chair and the couch sit around it on bare floor, and the furniture looks like it's waiting to be arranged.
The fix is almost always the same. Size up.
The formula: measure, subtract, round down
- Measure the room wall to wall, length and width, at floor level.
- Take 2 to 3 feet off each measurement. That leaves 12 to 18 inches of bare floor between the rug and every wall.
- Round down to the nearest standard rug size.
That's it. It works for an apartment living room as well as a big family room, because it starts from your room, not from a list of sizes.
One room, worked through
Say your living room is 12 x 15 feet.
- 12 feet minus 3 feet is 9 feet.
- 15 feet minus 3 feet is 12 feet.
- The rug to order is a 9 x 12.
Laid down, it leaves about 18 inches of floor at every wall, and there's room for a sofa and two chairs to sit on its edges.
In the UK, the same idea in metric: leave 30 to 45 cm of floor at each wall, then pick the nearest standard size below. Most UK shops sell rugs in sizes like 160 x 230, 200 x 290 and 240 x 340 cm.
Leave 12 to 18 inches of floor at the walls
This is the number that makes a rug look planned. Less than 12 inches and it starts to look like wall-to-wall carpet that shrank in the wash. Much more than 18 and the rug looks like it's floating.
Front legs on: the rule that pulls it together
Every seat in the conversation should have at least its front legs on the rug. The couch, both armchairs, the ottoman. That's what ties the furniture into one group.
You don't need all four legs on. Front legs on, back legs on the floor, is the look most designers aim for, and it's the easiest to get in a real room.
Got a sectional or an L-shaped couch? Same rule. The rug needs to reach under the front legs along both runs of the L, which usually means going one size bigger than you'd buy for a straight sofa.
Between two sizes? Go bigger
If the formula lands you between two sizes, take the bigger one, as long as it still leaves 12 inches of floor at every wall.
A rug that's slightly too big almost never looks wrong. One that's too small always does.
The mistakes to skip
- The rug under the coffee table only. Size up until every seat has its front legs on.
- Buying by price before measuring. Measure first, then shop the size you need.
- A rug that catches two sofa legs and misses the rest. Either all the seats touch it, or none do. Half and half looks like a mistake.
FAQ
Should the rug go under the couch? Under the front legs, yes. It doesn't need to go all the way under unless the rug is big enough to sit under every piece with floor still showing at the walls.
What size rug for a small living room? The same formula works. In a small room, the formula may give you a 5 x 8 or a 6 x 9, and that's fine, as long as the front legs of the seating reach it.
Can a rug be too big? Yes, if it runs closer than about 12 inches to the walls. Then it reads as carpet rather than a rug.
Do I need a rug size calculator? No. Room length minus 2 to 3 feet, room width minus 2 to 3 feet, round down. That's the whole calculation.
The rest of the rules are in the book
This post covers one room. Right-Size Room, No. 03 in the Decorwick Measured Home Series, has the full Rug Finder for every room size in US and UK sizes, plus 40 layouts drawn to scale with the rug already placed, so you can find your room and copy it. See Right-Size Room
