How Long Is A 3-Seat Couch And Other Couch Sizes? Here Are The Standard Sofa Sizes And Dimensions.

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There are many different sofa sizes and dimensions depending on how many seats the couch has. For example, how long is a 3 seat couch? A three-seater sofa is usually 84″ long. But a 6-seat couch isn’t twice as long: it’s 171” long. This article clears up the confusion and includes all the standard sofa sizes and dimensions, plus a simple 3-step process to measure your space for a new couch.

Table Of Contents

What’s The Standard Sofa Size?

The standard three-seat couch is about 84” long, 40” deep, and 33” tall. Here are some more details on standard sofa sizes for different dimensions (length, depth, etc.):

  • Sofa length: 70-87″, most commonly 84″
  • Sofa depth: 32-40″, most commonly 35″ (from the very front to the very back)
  • Sofa height: 26-36″ (from the floor to the top of the sofa back)
  • Sofa seat depth: 20-25″ for standard, 28-35″ for deep-seat sofas (from the front edge of the seat to the back edge of the seat)
  • Seat height: 15-20″ (from the floor to the top of a sofa’s seat cushion)

How Long Is A Standard Sofa?

A standard sofa is 70-87″ long, usually 84″ long.

What’s The Height Of A Standard Sofa?

From the floor to the top of a couch’s seat cushion, a standard sofa’s height is 15-20″. From the floor to the very top of the couch’s back, most couches are 30 to 36” tall.

How Deep Should My Couch Be?

If you’re of short or average height, the standard seat depth of 20-25″ will probably work for you. If you’re closer to 6’ tall or more, look for a deep-seat sofa with 28-35″ in depth.

Standard Sofa Dimensions For Loveseats, Three Seater Sofas, Four Seaters, And Five Seaters

A loveseat with pale blue-green sofa cushions is in the corner of a room with floor-to-ceiling big windows looking out onto a beach and the ocean.

How Long Is A Loveseat? (Two Seater Sofa)

Loveseats tend to be 50” long in the seating area (not including the sofa arms). Other loveseat dimensions are 20-24 inches in seat depth and 35 inches in total depth. Height and arm height vary.

How Long Is A 3-Seat Couch?

A standard three-seat sofa is usually 70″ to 87″ long in the seating area, most commonly 84″ long (not including arms). A three-seater couch that’s 84” long is 7 feet long.

How Long Is A 4-Person Couch?

A four-person couch is usually about 90″ long in the seating area (not including the couch arms).

How Long Is A 5-Person Couch?

A five-person couch is usually 108″ long in the seating area (not including the arms).

What Are The Standard Mattress Dimensions For A Sleeper Sofa?

Below are the standard mattress sizes for sleeper sofas:

  • Twin-size sleeper sofa mattress dimensions: 38″w x 72″d
  • Full-size sleeper sofa mattress dimensions: 52″w x 72″d
  • Queen-sleeper sofa mattress dimensions: 60″w x 72″d

Keep in mind two things: 1) standard couch dimensions on a sleeper sofa are different from the sofa’s overall dimensions (e.g., the two arms add bulk), and 2) sleeper-sofa mattresses are slightly different in size from standard bed mattresses.

How Do I Measure Space For A Sofa? Here Are The 3 Simple Steps To Make Sure A Couch Will Fit In Your Living Space.

Someone is using a yellow tape measure to measure a gray couch.

Step 1: Get A Measuring Tape

Measure the area you want to put the couch in, being aware of surrounding furniture like a coffee table. Ensure your couch can fit in the living space with the other furniture. Measure doorways and hallways to ensure you can fit the couch through it when you move it in.

If you want a physical feel for the available space, you can also use masking tape to outline the shape of where you want to put the sofa. Then, sit in the taped-off area and try to imagine a sofa there: does the living space feel cramped or not?

Step 2: Write Down The Available Space’s Dimensions

Using pen and paper or a notes app on your phone, write down the dimensions of the area the couch will go in. Here are some examples of things to think about:

  • If there’s a window you don’t want to block, note how high off the floor the windowsill is so you can look for the right sofa height.
  • If you want to put a side table next to the couch, leave enough extra space for that.
  • If you’re putting your couch near a doorway, ensure the total sofa depth won’t block the doorway.
  • If you’re buying a sleeper sofa, ensure the area has enough space for the sleeper sofa to extend to the sleeping position or that whatever is in its way is easy to move.

Step 3: Shop For A Sofa That Fits Your Dimensions

Take a measuring tape with you to showrooms and measure sofas to be sure they’ll fit. If you’re shopping online, check all the dimensions of your desired sofa — and if the seller doesn’t provide measurements, ask for them or don’t buy the sofa. As you can see from this article, the range of standard sofa dimensions can vary greatly, so it’s better safe than sorry.

If you’re ordering online, check for the packaging dimensions to make sure you can fit the couch through a small doorway, if necessary.

Here are some standard dimensions to measure:

  • Length: measure from one arm to the other, taking the measurement at the couch’s widest point
  • Height: measure from the floor to the highest point of the couch’s back
  • Depth: measure from the front edge of the sofa cushion all the way to the back of the couch. It’ll be easiest to do this from one of the sides of the sofa.
  • Diagonal depth: on one of the short sides of the couch, measure in a straight line from the top left corner of the couch to the bottom right corner. 
  • Diagonal width: facing the back of the couch, measure from the top right corner of the couch to the bottom left corner of the couch. This ensures the sofa will fit through tight corners, stairwells, and elevators. 

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Lucy Henderson is a Seattle-based home décor expert and creator of Palladio Interiors. She loves writing about design trends, home-interior inspiration, and home-decorating tips. She's a fan of coziness and simplicity.