A sofa that’s too small looks lost in the room; one that’s too big swallows it whole. Designers solve this with a simple proportion rule — the sofa should span roughly two-thirds of its wall — and our free sofa size calculator applies that rule to your exact room, then the sofa size calculator checks depth and walkway clearance so the whole layout breathes.

Open the Sofa Size Calculator →

What the Sofa Size Calculator Tells You (Specifications)

• Inputs: wall length in feet, room depth in feet, and seats needed (2, 3 or 4+).
• Ideal length range — 60–75% of your wall length in inches, with a floor based on seat count (60″ for 2 seats, 78″ for 3, 96″ for 4+).
• Ideal depth — 36–40″ standard, or 40–44″ lounge depth for rooms 12 ft or deeper.
• Walkway check — how much clearance remains in front of the sofa, with a warning if it drops under 36″.

How to Use It — Step by Step

1. Measure the wall where the sofa will sit, in feet.
2. Measure the room depth — wall to opposite wall (or to the next furniture zone).
3. Enter both numbers and choose how many seats you need.
4. Hit calculate. You’ll get a length range, a depth recommendation and a clearance verdict.
5. Shop within the range — and use our coffee table size calculator next, since the table must be sized to the sofa.

Designer Tips for Sofa Sizing

• Two-thirds is the magic fraction. A 14 ft wall wants a sofa around 112–126″ — anything much smaller looks apologetic.
• Float large sofas in big rooms rather than pushing them against the wall; it defines the seating zone.
• Depth is comfort. Under 38″ suits formal sitting rooms; 40″+ is for real lounging.
• Check the doorway path too — the sofa has to get into the room, not just fit in it.

FAQs

What size sofa for a 12×12 living room?
Around 84–96″ long and 36–38″ deep — big enough to anchor the room without killing the walkways. Run your exact wall through the calculator.

How much space should be around a sofa?
At least 30″ of walkway, 36″ ideally. 18″ between sofa and coffee table.

Is a 3-seater sofa 84 inches?
Typically 78–90″. The calculator adjusts the minimum by seat count so you never undersize.

Get it right the first time — open the free sofa size calculator and shop with confidence.