Short answer: A sofa is one straight run of seats. A sectional is made of several connected pieces that turn a corner or add a chaise, usually in an L or a U. If your seating wall is the only place you can put furniture, a sofa is the simplest choice. If you have a corner to fill or want a built-in lounging spot, a sectional makes better use of the floor. A modular sofa can be set up as a straight sofa, an L-shape or a U-shape, so you can pick the shape that fits your room today and change it later.
The right answer depends less on the name and more on three things: the size of your room, where the walkways run and how many people sit together. The sections below walk through each one using the real footprints of our modular collections.
On This Page
- What is the difference between a sofa and a sectional?
- L-shaped vs. U-shaped sectional: what is the difference?
- Can a modular sofa become an L-shape or a U-shape?
- How do I choose by room size and layout?
- Is a modular sofa or a traditional sectional better for a small room?
- How do I choose a sectional for a corner living room?
- Our recommendation
- Explore our sofas and sectionals
What is the difference between a sofa and a sectional?
The difference is the shape and the number of pieces. A sofa has seats in a single line, with an arm at each end or no arms at all. A sectional connects separate sections, such as seats, a corner piece and a chaise, into a layout that wraps around part of the room.
- Sofa: one straight run of two, three or four seats. It sits on one wall and leaves the rest of the room open.
- Sofa with a chaise: a straight sofa with one extended seat where you can put your legs up. The extra length goes in front of the sofa, not along the wall.
- L-shaped sectional: one run of seats along a wall and a second run at 90 degrees, joined by a corner module.
- U-shaped sectional: seating on three sides of a space, which closes off part of the room.
Some sectionals are sold as one fixed shape. Our modular sofas are built from separate modules, so the same collection can be a sofa, a sectional or a larger sectional. Our guide to modular sofas explains how the modules connect.
L-shaped vs. U-shaped sectional: what is the difference?
An L-shaped sectional has two legs that meet at a corner. A U-shaped sectional has three sides, with a second corner and a second return, so it seats more people and takes up much more floor.
L-shaped vs. U-shaped sectional: what is the difference?
| Straight sofa | Sofa with chaise | L-shaped sectional | U-shaped sectional | |
|---|---|---|---|---|
| Shape | One straight run | Straight run plus a forward extension | Two runs joined at a corner | Three runs, two corners |
| Floor use | One wall | One wall plus the chaise depth | Two walls or a corner | Three sides of a space |
| Typical seating | Two to four | Two to four, with one lounging seat | Three to four | Four or more |
| Best for | Narrow rooms, a single wall | Rooms with extra depth in front of the sofa | Corners and mid-size rooms | Large or open-plan rooms |
The seating counts are general guidance, not a product specification. People sit differently, and in a corner seat many people lounge rather than sit upright. Our Cassini, Gaia, Ciello, Atmosphere, Neptune and Orian collections can all be built as an L-shape or a U-shape, and Cassini also has angled wedge modules for a softer turn at the corner.
Can a modular sofa become an L-shape or a U-shape?
Yes. A modular sofa is a set of modules that connect, so adding a corner module and more seats turns a straight sofa into an L, and a second corner turns an L into a U. You choose the arrangement in the product configurator, then rearrange or add modules later if your room changes.
Here is what each of our six sofa collections offers, based on the live configurators.
Can a modular sofa become an L-shape or a U-shape?
| Collection | L-shape (corner) | U-shape | Chaise or ottoman | Good to know |
|---|---|---|---|---|
| Ciello | Yes, left or right corner | 4-seat and 6-seat U | Chaise (left or right), ottoman | A two-seater with two arms and a chaise is 74.75 x 68.5 inches |
| Gaia | Yes, left or right corner | 4-seat, 6-seat and 7-seat U | Chaise (left or right), ottoman | The compact armless layout (armless seat, corner and seat) is 65.4 x 65.4 inches |
| Atmosphere | Yes, left or right corner | 6-seat and 7-seat U | Chaise, ottoman, long ottoman | Regular, storage and sleeper modules cannot be mixed in one sofa |
| Cassini | Yes, plus angled wedge modules | 4-seat and 6-seat U | Wedge modules instead of a chaise | A compact L fits within roughly 62.5 inches on each side |
| Neptune | Yes, left or right corner | 6-seat and 7-seat U | Ottoman with chaise option | Sofa bed with storage in the sleeper seats; both arms are required |
| Orian | Yes, left or right corner | 6-seat and 7-seat U | Ottoman | Sofa bed; both arms are required |
The footprints are for the exact arrangements named, so they are not the size of all corner or chaise layouts in a collection. Build your exact layout in the configurator and read the full dimensions on the product page. For more on the corner and chaise options, see our guide to which sofa configuration fits your living room.
How do I choose by room size and layout?
Start with the floor, not the sofa. Measure the wall or walls you can use, then leave room to walk. Our own planning target is about 30 inches for a useful walking route, with 24 inches possible in a tight home and 36 inches more comfortable. Leave about 18 inches between the sofa and a coffee table. These are general guidelines, not product specifications.
- Under about 200 square feet: a sofa, or a short L along one wall. Choose a shallower seat to save floor.
- About 200 to 300 square feet: a mid-size L-shape fits with clearance on the open sides.
- Over about 300 square feet: a larger L, a sofa with a chaise or a U-shape works without crowding the room.
- Narrow room: a straight sofa, or a sofa with a chaise if you have extra depth, usually works better than an L.
- Square or open-plan room: an L or a U can define the seating area and separate it from the rest of the space.
Draw a rectangle on the floor with painter's tape for each leg of the layout, then walk around it. Our sectional sofa size guide shows the full measuring steps.
Is a modular sofa or a traditional sectional better for a small room?
For most small rooms, a modular sofa is the more flexible choice, because you choose how many modules you buy and how they sit. A small L can be quite compact: a compact Cassini L fits within roughly 62.5 inches on each side. A two-seater with a chaise in our Ciello collection is 74.75 x 68.5 inches, which keeps the length short but projects forward.
There are honest trade-offs. Removing the arms saves width but removes a place to lean. A corner seat often works better for lounging than as a third upright seat, so a small L may seat two adults more comfortably than three. A traditional fixed sectional can still be a good choice if it fits and you do not expect to move or change the layout. If the room is very small, a straight sofa has the smallest footprint of all.
Modular pieces also arrive in separate boxes, which can help in tight stairs and elevators. Our guide to measuring stairs, elevators and doorways explains how to check access before you order, and our list of the best small sectional sofas under 90 inches compares compact L-shapes in more detail.
How do I choose a sectional for a corner living room?
A corner room is where an L-shaped sectional works best, because the corner module sits in the corner and the two legs follow the two walls. The common mistake is to measure only the longer wall. Measure both legs, because each one is a separate length that has to fit.
- Measure both walls: note windows, vents, doors and any wall that a door opens against, then subtract the walking space from each leg.
- Pick the orientation: sectionals are described as left or right facing. A left-hand corner can work well while the mirror image blocks a doorway, so sketch both before you choose. With our modular collections, corner layouts can be reversed by rearranging the pieces, although arms are handed in some collections, so check the arm modules too.
- Think about the corner seat: it is often best used as a lounging spot. In a small corner, plan on two adults sitting comfortably rather than three upright seats.
- Decide on arms: Ciello, Gaia, Cassini and Atmosphere can be set up with two, one or no arms where the layout allows, which saves width. Neptune and Orian need both arms.
- Add a table last: a round or square coffee table is easier to walk around in front of an L. Our guide to choosing a coffee table covers sizes.
If the corner is shallow, a U may not fit at all, so check the three sides before you consider one.
Our recommendation
Choose by the room, then by the lifestyle.
- One main wall, narrow room or small studio: a straight sofa, or a sofa with a chaise if you have extra depth in front of it.
- A corner, or a mid-size room where you want more seating: an L-shaped modular sectional. Our Cassini collection has a compact L that fits within roughly 62.5 inches on each side.
- A large or open-plan room with a group that sits together: a U-shaped sectional, with enough floor for walkways on the open side.
- A home that may change: a modular sofa, so you can add or rearrange modules rather than replace the whole piece.
- Guests who stay over: our Neptune and Orian sofa beds can be built as sectionals too.
If you want a second opinion on your room, you can book a free design consultation with our team.
Explore our sofas and sectionals
Product specifications can change. Check the current dimensions on the product page before ordering.